Action Physics
Action in
physics is a
numerical value describing how a
physical system
has
changed over
time. Action is
significant because the equations of
motion of the
system can be derived through the
principle of stationary action. In the simple case of a single
particle moving with a
specified
velocity, the action is the
momentum of the particle times the
distance it
moves, added up along its path,
or equivalently, twice its
kinetic energy times the length of time for which it has that amount
of energy, added up over the period of time under consideration. For more
complicated systems, all such quantities are added together. More
formally, action is a mathematical functional which takes the
trajectory, also called path or history, of the
system as its argument and has a real number as its result. Generally, the
action takes different values for different paths. Action has dimensions
of
energy ×
time or
momentum ×
length, and its SI unit is joule-second (like the Planck constant h).
Action Theory in
philosophy is the processes causing
willful
human bodily
movements of a more or less complex kind. The trait of
being active and
energetic and
forceful. The
operating part that
transmits power to a
mechanism.
Motion -
Momentum -
Potential -
Speed -
Flight -
Spin -
Elastic
-
Physics
Reaction
in
physics is that
all
forces occur in pairs such that if one object exerts a
force on
another object, then the second object exerts an equal and opposite
reaction
force on the first. The third law is also more generally stated
as: "To every action there is always
opposed an equal reaction: or the
mutual actions of two bodies upon each other are always equal, and
directed to contrary parts." The attribution of which of the two
forces is
the action and which is the reaction is arbitrary. Either of the two can
be considered the action, while the other is its associated
reaction.
Principle
of Least Action is a
variational principle that, when
applied to the action of a
mechanical system, can be used to obtain the
equations of
motion for that system.
Principle of Least Effort
-
Water.
Stillness is
an
illusion. Everything is moving.
If standing still on Earth you're moving 800 miles per second or
2,880,000 MPH. "All entities
move and nothing remains still" -
Heraclitus.
Action Formulas
The units of
Action are
Energy times
Time,
or
ML2/T (
Mass
x
Length x
Length /
Time).
Speed is the magnitude of its
velocity (the rate of change
of its position).
Acceleration.
Velocity of an object is the rate of change of its position
with respect to a
frame of reference, and is a function of time.
Duration
is the amount of
elapsed time between two events.
Rotation -
Pendulum -
Momentum
D = V x T (
Distance equals
Velocity multiplied by
Time)
Flight -
Gravity -
Pressure -
Motion -
E = mc²
Action has the
dimension of Energy x Time, where a
physical system follows simultaneously all possible paths
with amplitudes determined by the action. For the action
integral to be well defined the
trajectory has to be bounded in time and space.
Spatial Intelligence -
Time Management.
Force
Force is any
interaction
that, when unopposed, will change the
motion of an object. In other words,
a force can cause an object with
mass to change its
velocity (which
includes to begin moving from a state of rest), i.e., to
accelerate. Force
can also be described by intuitive concepts such as a push or a pull. A
force has both magnitude and direction, making it a vector quantity. It is
measured in the SI
unit
of newtons and represented by the symbol F.
Isaac
Newton.
F = ma (Force equals
mass times acceleration). The net force on an object is equal to the mass
of the object multiplied by the
acceleration of the object.
Least
Effort -
Snells LawAgency is the state of
being in action or exerting power. How a
result
is obtained or an end is achieved.
Control -
Agency.
Work = Force X Distance W=FxD
work(
jules), F(newtons), D(meteres).
Image Sample (photo)
-
Image Sample (photo).
Restoring Force is a force that gives rise to an
equilibrium in a
physical system. If the system is perturbed away from the equilibrium, the
restoring force will tend to bring the system back toward equilibrium. The
restoring force is a function only of position of the mass or particle. It
is always directed back toward the equilibrium position of the system. The
restoring force is often to in simple harmonic motion. The force which is
responsible to restore original size and shape is called restoring force.
An example is the action of a
spring. An idealized spring exerts a force
that is proportional to the amount of deformation of the spring from its
equilibrium length, exerted in a direction to oppose the deformation.
Pulling the
spring to a greater length causes it to exert a force that brings the
spring back toward its equilibrium length. The amount of force can be
determined by multiplying the spring constant of the spring by the amount
of stretch. Another example is of a
pendulum. When
the pendulum is not swinging all the forces acting on the
pendulum are in
equilibrium. The force due to gravity and the mass of the object at the
end of the pendulum is equal to the tension in the string holding that
object up. When a pendulum is put in motion the place of equilibrium is at
the bottom of the swing, the place where the pendulum rests. When the
pendulum is at the top of its swing the force bringing the pendulum back
down to this midpoint is gravity. As a result
gravity can be seen as the
restoring force in this. Restoring force of a spring : ( f=-kx ).
Conservative Force is a force with the property that the work done in
moving a particle between two points is independent of the taken path.
Equivalently, if a particle travels in a closed loop, the net work done
(the sum of the force acting along the path multiplied by the
displacement) by a conservative force is zero. A conservative force is
dependent only on the position of the object. If a force is conservative,
it is possible to assign a numerical value for the potential at any point.
When an object moves from one location to another, the force changes the
potential energy of the object by an amount that does not depend on the
path taken. If the force is not conservative, then defining a scalar
potential is not possible, because taking different paths would lead to
conflicting potential differences between the start and end points.
Gravitational Force is an
example of a conservative force, while
Frictional
Force is an example of a non-conservative force. Other examples of
conservative forces are: force in elastic spring, electrostatic force
between two electric charges, magnetic force between two magnetic poles.
The last two forces are called central forces as they act along the line
joining the centres of two charged/magnetized bodies. Thus, all central
forces are conservative forces.
Harmonic Oscillator is a system that, when displaced from
its equilibrium position, experiences a restoring force, F, proportional
to the displacement, x:
Centrifugal
Force is used to refer to an inertial force directed away from the
axis of rotation that appears
to act on all objects when viewed in a
rotating reference frame.
Centrifugal Force is an inertial force (also called a "fictitious" or
"pseudo" force) that appears to act on all objects when viewed in a
rotating frame of reference. It is directed away from an axis passing
through the coordinate system's origin and parallel to the axis of
rotation. If the axis of rotation passes through the coordinate system's
origin, the centrifugal force is directed radially outwards from that
axis. The concept of centrifugal force can be applied in rotating devices,
such as
centrifuges,
centrifugal pumps,
centrifugal governors, and
centrifugal clutches, and in
centrifugal railways, planetary
orbits and
banked curves, when they are analyzed in a rotating coordinate system. The
term has sometimes also been used for the reactive centrifugal force that
may be viewed as a reaction to a centripetal force in some circumstances.
Filtering.
Centripetal Force is a force that
makes a body follow a curved path.
Its direction is always orthogonal to the motion of the body and towards
the fixed point of the instantaneous center of
curvature of the path.
Isaac Newton described it as "a force by which bodies are drawn or
impelled, or in any way tend, towards a point as to a centre". In
Newtonian mechanics, gravity provides the centripetal force causing
astronomical orbits. One common example involving centripetal force is the
case in which a body moves with uniform speed along a circular path. The
centripetal force is directed at right angles to the motion and also along
the radius towards the centre of the circular path. Centripetal force is
defined as the force that is necessary to keep an object moving in a
curved path and that is directed inward toward the center of rotation,
while centrifugal force is defined as the apparent force that is felt by
an object moving in a curved path that acts outwardly away from the center
of rotation, according to Merriam Webster Dictionary.
Fans -
Propellers -
Spin
Coriolis Force
is an inertial force or
fictitious force that acts on objects that are in motion relative to
a
rotating reference frame. In a reference frame with
clockwise
rotation, the force acts to the left of the
motion of the object. In one
with
anticlockwise rotation, the force acts to the right. Though
recognized previously by others, the mathematical expression for the Coriolis force appeared in an 1835 paper by French scientist
Gaspard-Gustave de Coriolis, in connection with the theory of
water wheels. Early in the 20th century, the term Coriolis force began to
be used in connection with
meteorology. Deflection of an object due to the Coriolis force is called the 'Coriolis effect'.
Ocean Currents -
Hurricanes.
Fictitious Force is an apparent force that acts on all masses whose
motion is described using a non-inertial frame of reference, such as a
rotating reference frame.
If two individual forces are of equal magnitude and opposite
direction, then the forces are said to be balanced. An object is said to
be acted upon by an unbalanced force only when there is an individual
force that is not being balanced by a force of equal magnitude and in the
opposite direction.
Magnetics -
Reaction Force -
E = mc²
Impulse in physics is the integral of a force, F, over the time
interval, t, for which it acts. Since force is a vector quantity, impulse
is also a vector quantity. Impulse applied to an object produces an
equivalent vector change in its linear
momentum,
also in the resultant direction. A resultant force causes acceleration and
a change in the velocity of the body for as long as it acts. A resultant
force applied over a longer time, therefore, produces a bigger change in
linear momentum than the same force applied briefly: the change in
momentum is equal to the product of the average force and duration.
Conversely, a small force applied for a long time produces the same change
in
momentum—the same impulse—as a larger force
applied briefly.
Chain Fountain is a counterintuitive physical phenomenon observed with
a chain of beads placed inside a jar, and then one end of the chain is yanked
from the jar and is allowed to fall to the floor beneath. This establishes
a
self-sustaining flow of the chain of beads which
rises up from the jar
into an arch ascending into the air over and above the edge of the jar
with a noticeable gap, and down to the floor or ground beneath it, as if
being sucked out of the jar by an invisible
siphon. This phenomenon is also known as the
self-siphoning beads or
the Mould effect.
Electromotive
Force is the voltage developed by any source of
electrical energy such
as a
battery or
dynamo. It is generally
defined as the electrical potential for a source in a
circuit. A
device that supplies electrical energy is called electromotive force or emf. Emfs convert chemical, mechanical, and other forms of energy into
electrical energy. The product of such a device is also known as emf.
Recoil is the backward movement of a gun when it is discharged. In
technical terms, the recoil
momentum acquired by
the gun exactly balances the forward momentum of the projectile and
exhaust gases (ejecta), according to Newton's third law, known as
conservation of
momentum. In hand-held small arms, the recoil momentum is
transferred to the ground through the body of the shooter; while in
heavier guns such as mounted machine guns or cannons, recoil momentum is
transferred to the ground through the mount.
World's Heaviest
Weight (youtube) - By calibrating your
Force Transducer on
the world's biggest weight - 1,000,000 pounds of force. This machine
ensures planes don't break apart, jets provide required thrust, and
rockets make it to their destination.
Futek.
As your cornering speed increases,
the force pushing you to the outside of the turn increases. These forces
are absorbed by your car's suspension resulting in the body leaning to the
outside of the corner. On the free upper part, there is centrifugal force
which is caused by the inertia of the free upper part of your body tending
to continue in a straight line as the car makes a turn to the right. Thus,
the upper part of your body tends to lean left as the car turns right.
Chariot Racing
(wiki).
Bicycle and Motorcycle Dynamics is the science of the motion of
bicycles and motorcycles and their components, due to the forces acting on
them. Dynamics falls under a branch of physics known as classical
mechanics. Bike motions of interest include balancing, steering, braking,
accelerating, suspension activation, and vibration. The study of these
motions began in the late 19th century and continues today. Bicycles and
motorcycles are both single-track vehicles and so their motions have many
fundamental attributes in common and are fundamentally different from and
more difficult to study than other wheeled vehicles such as dicycles,
tricycles, and quadracycles. As with unicycles, bikes lack lateral
stability when stationary, and under most circumstances can only remain
upright when moving forward. Experimentation and mathematical analysis
have shown that a bike stays upright when it is steered to keep its center
of mass over its wheels. This steering is usually supplied by a rider, or
in certain circumstances, by the bike itself. Several factors, including
geometry, mass distribution, and gyroscopic effect all contribute in
varying degrees to this self-stability, but long-standing hypotheses and
claims that any single effect, such as gyroscopic or trail, is solely
responsible for the stabilizing force have been discredited. While
remaining upright may be the primary goal of beginning riders, a bike must
lean in order to maintain balance in a turn: the higher the speed or
smaller the turn radius, the more lean is required. This balances the roll
torque about the wheel contact patches generated by centrifugal force due
to the turn with that of the gravitational force. This lean is usually
produced by a momentary steering in the opposite direction, called
counter-steering. Countersteering skill is usually acquired by motor
learning and executed via procedural memory rather than by conscious
thought. Unlike other wheeled vehicles, the primary control input on bikes
is steering torque, not position. Although longitudinally stable when
stationary, bikes often have a high enough center of mass and a short
enough wheelbase to lift a wheel off the ground under sufficient
acceleration or deceleration. When braking, depending on the location of
the combined center of mass of the bike and rider with respect to the
point where the front wheel contacts the ground, bikes can either skid the
front wheel or flip the bike and rider over the front wheel. A similar
situation is possible while accelerating, but with respect to the rear
wheel.
A cyclist must lean into a turn to
prevent tipping over in the other direction. The
frictional force provides the centripetal
force necessary to turn the cyclist to the left. But the frictional force
also produces a clockwise torque that will cause the rider and bicycle to
tip clockwise to the right. When a car or truck makes a turn it cannot
lean into the turn. The torque that prevents it from tipping away from the
turn arises from the normal force on the outside tires being larger than
the normal force on the inside tires.
Countersteering
is used by single-track vehicle operators, such as cyclists and
motorcyclists, to initiate a turn toward a given direction by momentarily
steering counter to the desired direction ("steer left to turn right"). To
negotiate a turn successfully, the combined center of mass of the rider
and the single-track vehicle must first be leaned in the direction of the
turn, and steering briefly in the opposite direction causes that lean. The
rider's action of countersteering is sometimes referred to as "giving a
steering command". The scientific literature does not provide a clear and
comprehensive definition of countersteering. In fact, "a proper
distinction between steer torque and steer angle is not always made.
Center of Mass.
Pressure
Pressure
is the
force applied perpendicular to the surface of an object
per unit area over which that force is distributed.
F = Force applied by the body.
A = Total area of the object.
Where, h is the height, ρ is density, g is gravity. Pressure Formula
is used to calculate pressure, force, area, density, height and gravity if
some of these quantities are given. Pressure is expressed in Pascal (Pa).
Boyle's Law is an
experimental gas law that describes how the pressure of a
gas tends to increase as the
volume of the container decreases. A modern statement of Boyle's law
is the absolute pressure exerted by a given mass of an ideal gas is
inversely proportional to the volume it occupies if the temperature and
amount of gas remain unchanged within a closed system. The pressure law
states that for a constant volume of gas in a sealed container the
temperature of the
gas is directly proportional
to its pressure. This can be easily understood by visualizing the
particles of gas in the container moving with a greater
energy when the temperature is
increased.
Wind Pressure
-
Wing Pressure -
Barometric Pressure
(High Pressure / Low Pressure) -
Water Pressure Compressor
-
Breathing
-
Vacuum -
Negative Pressures
(wiki) - Positive
Pressure Room
Partial
Pressure. In a
mixture of
gases, each constituent gas has a partial pressure which is the
notional pressure of that constituent gas if it alone occupied the entire
volume of the original mixture at the same temperature. The total pressure
of an ideal gas mixture is the sum of the partial pressures of the gases
in the mixture. The partial pressure of a gas is a measure of
thermodynamic activity of the gas's molecules. Gases dissolve, diffuse,
and react according to their partial pressures, and not according to their
concentrations in gas mixtures or liquids. This general property of gases
is also true in chemical reactions of gases in biology. For example, the
necessary amount of oxygen for human respiration, and the amount that is
toxic, is set by the partial pressure of oxygen alone. This is true across
a very wide range of different concentrations of oxygen present in various
inhaled breathing gases or dissolved in blood. The partial pressures of
oxygen and carbon dioxide are important parameters in tests of arterial
blood gases, but can also be measured in, for example, cerebrospinal
fluid.
Pressure Sensor is a device for pressure
measurement of gases or
liquids. Pressure is an
expression of
the force required to stop a fluid
from expanding, and is usually stated in terms of force per unit
area. A pressure sensor usually acts as a
transducer; it generates a
signal as a function
of the pressure imposed, such a signal is electrical. Pressure sensors are
used for control and monitoring in thousands of everyday applications.
Pressure
sensors can also
be used to indirectly measure other
variables such as
fluid/gas flow, speed, water level, and altitude. Pressure sensors can
alternatively be called pressure transducers, pressure transmitters,
pressure senders, pressure indicators,
piezometers and manometers,
among other names.
Body Senses Pressure
Pressure Measurement is the analysis of an applied force by a
fluid (liquid or gas) on
a surface. Pressure is typically measured in units of force per unit of
surface area. Many techniques have been developed for the measurement of
pressure and vacuum. Instruments used to measure and display pressure in
an integral unit are called pressure gauges or vacuum gauges. A manometer
is a good example as it uses a column of liquid to both measure and
indicate pressure. Likewise the widely used Bourdon gauge is a mechanical
device which both measures and indicates and is probably the best known
type of gauge.-
Pressure Gage is an instrument indicating pressure.
Pascal unit is the SI derived unit of pressure used to quantify
internal pressure, stress, Young's modulus and ultimate tensile strength.
It is defined as one newton per square metre. Common multiple units of the
pascal are the hectopascal (1 hPa = 100 Pa) which is equal to one
millibar,
and the kilopascal (1 kPa = 1000 Pa) which is equal to one centibar. The
unit of measurement called standard atmosphere (atm) is defined as 101325
Pa. Meteorological reports typically state atmospheric pressure in millibars. (symbol: Pa).
Pressure Cooking
is the process of
cooking food, using
water or
other cooking liquid, in a sealed vessel known as a pressure cooker. This
simulates the effects of long braising within a shorter time. Almost any
food that can be cooked in steam or water-based liquids can be cooked in a
pressure cooker. The cooker works by trapping the steam produced from
boiling the cooking liquid inside the vessel. This causes internal
pressure and temperature to rise quickly. After use, the
steam is slowly
released so that the vessel can be opened safely.
Cabin Pressurization is a process in which conditioned air is pumped
into the cabin of an
aircraft or
spacecraft in order to
create a safe and comfortable environment for passengers and crew flying
at high altitudes. For aircraft, this air is usually bled off from the gas
turbine engines at the compressor stage, and for spacecraft, it is carried
in high-pressure, often cryogenic tanks. The air is cooled, humidified,
and mixed with recirculated air if necessary before it is distributed to
the cabin by one or more environmental control systems. The cabin pressure
is regulated by the outflow valve.
Momentum
Momentum is the product of the mass and
velocity of an
object.
P = momentum. M = mass. V = velocity.
Moment of Inertia determines the
torque needed for a desired
angular acceleration about a
rotational axis.
Angular Momentum is the
rotational analog of linear
momentum, which is a vector quantity defined as the product of an object's
mass, m, and its velocity, v. Linear momentum is denoted by the letter p
and is called “momentum” for short.
Linear momentum is defined as the product
of a system's
mass multiplied
by its
velocity.
What IS Angular Momentum?? (youtube).
Conservation of Angular Momentum in a closed system, no torque can be
exerted on any matter without the exertion on some other matter of an
equal and opposite torque. Hence, angular momentum can be exchanged
between objects in a closed system, but total angular momentum before and
after an exchange remains constant (is conserved). Seen another way, a
rotational analogue of Newton's first law of motion might be written, "A
rigid body continues in a state of uniform rotation unless acted by an
external influence." Thus with no external influence to act upon it, the
original angular momentum of the system remains constant. The law of
conservation of angular momentum states that when no external torque acts
on an object, no change of angular momentum will occur.
Orbitronics: New material property advances energy-efficient tech.
Researchers are also exploring the possibility of using the
orbital angular momentum of electrons orbiting their atomic nucleus:
an emerging field known as orbitronics. This field holds great promise for
memory devices, particularly because a large magnetisation could
potentially be generated with relatively small charge currents, leading to
energy-efficient devices. The million-dollar question now is identifying
the right materials to generate flows of OAMs, a prerequisite for
orbitronics. Whereas electronics uses the charge of the electron to
transfer information, technology of the future with less environmental
impact might use a different property of electrons to process information.
Until recently, the main contender for a different type of 'tronics' has
been
spintronics. Here, the property used to transfer
information is the spin of the electron. Discovery of orbital angular
momentum monopoles boosts the emerging field of orbitronics, an
energy-efficient alternative to electronics. Orbital angular momentum
monopoles have been the subject of great theoretical interest as they
offer major practical advantages for the emerging field of orbitronics, a
potential energy-efficient alternative to traditional electronics. Now,
through a combination of robust theory and experiments, their existence
has been demonstrated.
Four-Momentum is the generalization of the classical three-dimensional
momentum to four-dimensional
spacetime. Momentum is a vector in three dimensions; similarly
four-momentum is a four-vector in spacetime.
Energy–Momentum Relation is the relativistic equation relating total
energy (which is also called relativistic energy) to invariant mass (which
is also called rest mass) and momentum. This equation holds for a body or
system, such as one or more particles, with total energy
E, invariant mass m0, and momentum of
magnitude
p; the constant c is the
speed of light.
Inertia
is the
resistance of any physical object to any change in its state of
motion (this includes changes to its speed, direction or state of rest).
Inertia is also defined as the tendency of objects to keep moving in a
straight line at a constant
velocity. A property
of matter by which it continues in its existing state of rest or uniform
motion in a straight line, unless that state is
changed by an external
force. There is no measurable
difference between gravitational mass and
inertial mass.
List of
Moments of Inertia is the mass moment of inertia, usually denoted by
I, measures the extent to which an object resists rotational acceleration
about a particular axis, and is the rotational analogue to mass. Mass
moments of inertia have units of dimension ML2([mass] × [length]2). It
should not be confused with the second moment of area, which is used in
bending calculations. The mass moment of inertia is often also known as
the rotational inertia, and sometimes as the angular mass.
Quantized
Inertia is a fringe theory of inertia. (Unruh radiation and horizon
mechanics).
Negative Mass.
Inertial Frame of Reference in classical physics and special
relativity is a frame of reference in which a body with zero net force
acting upon it is not accelerating; that is, such a body is at rest or it
is moving at a constant speed in a straight line. In analytical terms, it
is a frame of reference that describes time and space homogeneously,
isotropically, and in a time-independent manner. Conceptually, the physics
of a system in an inertial frame have no causes external to the system. An
inertial frame of reference may also be called an inertial reference
frame, inertial frame, Galilean reference frame, or inertial space.
Non-Inertial Reference Frame is a frame of reference that is
undergoing acceleration with respect to an inertial frame. An
accelerometer at rest in a non-inertial frame will in general detect a
non-zero acceleration. In a
curved
spacetime all frames are non-inertial. The laws of motion in
non-inertial frames do not take the simple form they do in inertial
frames, and the laws vary from frame to frame depending on the
acceleration. To explain the motion of bodies entirely within the
viewpoint of non-inertial reference frames, fictitious forces (also called
inertial forces, pseudo-forces and d'Alembert forces) must be introduced
to account for the observed motion, such as the
Coriolis force or the
centrifugal force, as
derived from the acceleration of the non-inertial frame. As stated by
Goodman and Warner, "One might say that F = ma holds in any coordinate
system provided the term 'force' is redefined to include the so-called
'reversed effective forces' or 'inertia forces'.
Correspondence
Rules govern the principle of replacing physical quantities with
operators. Such replacements include energy and momentum, which can be
derived informally from taking the time and space derivities of the plane
wave function. These show a similarity to the
Heisenberg Uncertainty Principle, which is any of a variety of
mathematical inequalities asserting a fundamental limit to the precision
with which certain pairs of physical properties of a
particle, known as
complementary variables, such as position x and momentum p, can be known.
Gyro-Rotation
Gimbal is a pivoted
support that allows the
rotation of an object about a single axis. A set
of three gimbals, one mounted on the other with orthogonal
pivot axes, may
be used to allow an object mounted on the innermost gimbal to remain
independent of the rotation of its support (e.g. vertical in the first
animation). For example, on a ship: the gyroscopes, shipboard compasses,
stoves, and even drink holders typically use gimbals to keep them upright
with respect to the horizon despite the ship's pitching and rolling.
The Space Travel
Machine in the 1997 Movie named
Contact, was a film adaptation of
Carl
Sagan's 1985
novel.
Gyroscope is a spinning wheel or disc in which the axis of rotation is
free to assume any orientation by itself. When rotating, the orientation
of this axis is unaffected by tilting or rotation of the mounting,
according to the conservation of
angular momentum. Because of this,
gyroscopes are useful for measuring or maintaining orientation.
The main reason gyroscopes seem to defy gravity is the effective torque
applied to the spinning disc has on its angular momentum vector. The
influence of gravity on the plane of the spinning disc causes the
rotational axis to "deflect".
Gyroscopic Primer
by Prof Eric Laithwaite Full Video (youtube) - Anti Gravity Wheel.
Gyroscopic Effect is ability of the
rotating body to maintain a steady direction of its axis of rotation. The
gyroscopes are rotating with respect to the axis of symmetry at high
speed.
Perpetual Motion -
Anti-Gravity -
Generator -
Kinetic Energy -
Angular Momentum
The world's smallest optical gyroscope, Spinning the light. Engineers
create an optical gyroscope smaller than a grain of rice. The new
gyroscope from Hajimiri's lab achieves this improved performance by using
a new technique called "reciprocal sensitivity enhancement." In this
case, "reciprocal" means that it affects both beams of the light inside
the gyroscope in the same way. Since the
Sagnac Effect relies on
detecting a difference between the two beams as they travel in opposite
directions, it is considered nonreciprocal. Inside the gyroscope, light
travels through miniaturized optical waveguides (small conduits that carry
light, that perform the same function as wires do for electricity).
Imperfections in the optical path that might affect the beams (for
example, thermal fluctuations or light scattering) and any outside
interference will affect both beams similarly. Hajimiri's team found a way
to weed out this reciprocal noise while leaving signals from the Sagnac
effect intact. Reciprocal sensitivity enhancement thus improves the
signal-to-noise ratio in the system and enables the integration of the
optical gyro onto a chip smaller than a grain of rice.
Caster Angle is the angular displacement of the steering
axis from the vertical axis of a steered wheel in a car, motorcycle,
bicycle or other vehicle, measured in the longitudinal direction.
Precession is a change in the orientation of the
rotational
axis of a
rotating body. In an
appropriate reference frame it can be defined as a change in the first
Euler angle, whereas the third Euler angle defines the rotation itself. In
other words, if the axis of rotation of a body is itself rotating about a
second axis, that body is said to be precessing
about the second axis. A motion in which the second Euler angle changes is
called nutation. In physics, there are two types of precession:
torque-free and torque-induced. In astronomy, precession refers to any of
several slow changes in an astronomical body's rotational or orbital
parameters. An important example is the steady change in the orientation
of the axis of rotation of the Earth, known as the precession of the equinoxes.
Earth is fatter or bigger at the equator because of spin.
Magnus Effect is the commonly
observed effect
in which a spinning ball (or cylinder) curves away from its principal flight path.
Spin
Spinning is to
revolve quickly and
repeatedly around one's own axis.
Head Spin
(dizzy).
Centrifugal
Force -
Gyro -
Flywheel
Spin in physics is an intrinsic form of
angular
momentum carried by
elementary particles, composite particles (hadrons), and atomic nuclei.
Spin-1/2
an intrinsic property of all elementary
particles. All known
fermions, the particles that constitute ordinary matter, have a spin of
1/2. The spin number describes how many symmetrical facets a particle has
in one full rotation; a spin of 1/2 means that the particle must be fully
rotated twice (through 720°) before it has the same configuration as when
it started. Particles having net spin 1/2 include the proton, neutron,
electron, neutrino, and quarks. The dynamics of spin-1/2 objects cannot be
accurately described using classical physics; they are among the simplest
systems which require quantum mechanics to describe them. As such, the
study of the behavior of spin-1/2 systems forms a central part of quantum
mechanics.
Spinor
are elements of a complex vector space that can be associated with
Euclidean space. Like geometric vectors and more general
tensors,
spinors transform linearly when the Euclidean space is subjected to a
slight (infinitesimal) rotation. However, when a sequence of such small
rotations is composed (integrated) to form an overall final rotation, the
resulting spinor transformation depends on which sequence of small
rotations was used: unlike vectors and tensors, a spinor transforms to its
negative when the space is continuously rotated through a complete turn
from 0° to 360°. This property characterizes spinors: spinors can be
viewed as the "square roots" of vectors.
Proton Spinning is the reason why Everything Spins. (
above
and below).
Pulsars can Spin
as fast as Atoms.
Spintronics also
known as spin electronics, is the study of the intrinsic spin of the
electron and its
associated
magnetic moment,
in addition to its fundamental electronic charge, in
solid-state devices.
Molecular Spintronics. Chemists and physicists have designed,
deposited and operated single molecular spin switches on surfaces. The
newly developed molecules feature stable spin states and do not lose their
functionality upon adsorption on surfaces.
Practical spin wave transistor one step closer.
Heterostructures for Spintronics. Spintronic devices work with spin
textures caused by quantum-physical interactions. Scientists have now
studied graphene-cobalt-iridium heterostructures at BESSY II. The results
show how two desired quantum-physical effects reinforce each other in
these heterostructures. This could lead to new spintronic devices based on
these materials.
Data reveal a surprising preference in particle spin alignment.
Findings may point to a previously unknown influence of the strong
force--and a way to measure its local fluctuations. Given the choice of
three different 'spin' orientations, certain particles emerging from
collisions at the
Relativistic
Heavy Ion Collider, an atom smasher, appear to have a preference.
Recent results reveal a preference in global spin alignment of particles
called phi mesons. Conventional mechanisms -- such as the
magnetic field strength or
the swirliness of the matter generated in the particle collisions --
cannot explain the data. But a new model that includes local fluctuations
in the nuclear strong force can.
Novel nanowire fabrication technique paves way for next generation
spintronics. The challenge of fabricating nanowires directly on
silicon substrates for the creation of the next generation of electronics
has finally been solved. Next generation spintronics will lead to better
memory storage mechanisms in computers, making them faster and more
efficient.
Spin
Wave are propagating disturbances in the ordering of
magnetic materials. These
low-lying collective excitations occur in magnetic
lattices with
continuous symmetry. From the
equivalent quasiparticle point of view, spin waves are known as magnons,
which are boson modes of the spin lattice that correspond roughly to the
phonon excitations of the nuclear lattice. As temperature is increased,
the thermal excitation of spin waves reduces a ferromagnet's spontaneous
magnetization. The energies of spin waves are typically only μeV in
keeping with typical Curie points at room temperature and below. The
discussion of spin waves in
antiferromagnets is beyond the scope of this article.
Magnetic quantum material broadens platform for probing next-gen
information technologies. Scientists have used neutron scattering to
determine whether a specific material's atomic structure could host a
novel state of matter called a
spiral
spin liquid. By tracking tiny magnetic moments known as 'spins' on the
honeycomb lattice of a layered iron trichloride magnet, the team found the
first 2D system to host a spiral spin liquid.
Spin Ice
is a
magnetic substance
that does not have a single minimal-energy state. It has magnetic moments
(i.e. "spin") as elementary degrees of freedom which are subject to
frustrated interactions. By their nature, these interactions prevent the
moments from exhibiting a periodic pattern in their orientation down to a
temperature much below the energy scale set by the said interactions. Spin
ices show low-temperature properties, residual entropy in particular,
closely related to those of common
crystalline water ice.
A new
energy-efficient mechanism using the
Rashba effect. Scientists have proposed new quasi-1D materials for
potential spintronic applications, an upcoming technology that exploits
the spin of electrons. They performed simulations to demonstrate the spin
properties of these materials and explained the mechanisms behind their
behavior. Conventional electronics is based on the movement of
electrons and mainly concerns their electric charge; unfortunately, we are
close to reaching the physical limits for improving electronic devices.
However, electrons bear another intrinsic quantum-physical property called
"spin," which can be interpreted as a type of angular momentum and can be
either "up" or "down." While conventional electronic devices do not deploy
the spin of the electrons that they employ, spintronics is a field of
study in which the spin of the conducting electrons is crucial. Serious
improvements in performance and new applications can be attained through
"spin currents."
Nuclear spin's impact on biological processes uncovered. Researchers
have discovered that nuclear spin influences biological processes,
challenging long-held beliefs. They found that certain isotopes behave
differently in chiral environments, affecting oxygen dynamics and
transport. This breakthrough could advance biotechnology, quantum biology,
and NMR technology, with potential applications in isotope separation and
medical imaging.
GHz Rotation of
an Optically Trapped Nanoparticle in Vacuum. Rotating an optically
trapped silica nanoparticle in vacuum by transferring spin
angular
momentum of light to the particle's mechanical angular momentum. At
sufficiently low damping, realized at pressures below 10−5 mbar, we
observe rotation frequencies of single 100 nm particles exceeding 1 GHz.
We find that the steady-state rotation frequency scales linearly with the
optical trapping power and inversely with pressure, consistent with
theoretical considerations based on conservation of angular momentum.
Rapidly changing the polarization of the trapping light allows us to
extract the pressure-dependent response time of the particle's rotational
degree of freedom.
Gyrobus is an
electric bus that uses flywheel energy
storage, not overhead wires like a trolleybus. The name comes from the
Greek language term for flywheel, gyros. While there are no gyrobuses
currently in use commercially, development in this area continues.
Flywheel is a mechanical device which uses the conservation of
angular momentum to store rotational energy; a
form of
kinetic energy
proportional to the product of its moment of inertia and the square of its
rotational speed. In particular, assuming the flywheel's moment of inertia
is constant (i.e., a flywheel with fixed mass and second moment of area
revolving about some fixed axis) then the stored (rotational) energy is
directly associated with the square of its rotational speed.
Since flywheels act as mechanical energy
storage devices, they are the kinetic-energy-storage analogue to
electrical capacitors, for example, which are a type of accumulator. Like
other types of accumulators, flywheels smooth the ripple in power output,
providing surges of high power output as required, absorbing surges of
high power input (system-generated power) as required, and in this way act
as low-pass filters on the mechanical velocity (angular, or otherwise) of
the system. Common uses of a flywheel include: Smoothing the power output
of an energy source. For example, flywheels are used in reciprocating
engines because the active torque from the individual pistons is
intermittent. Energy storage systems. Delivering energy at rates beyond
the ability of an energy source. This is achieved by collecting energy in
a flywheel over time and then releasing it quickly, at rates that exceed
the abilities of the energy source. Controlling the orientation of a
mechanical system, gyroscope and reaction wheel. Flywheels are typically
made of steel and rotate on conventional bearings; these are generally
limited to a maximum revolution rate of a few thousand RPM. High energy
density flywheels can be made of carbon fiber composites and employ
magnetic bearings, enabling them to revolve at speeds up to 60,000 RPM (1
kHz). Carbon-composite flywheel batteries have recently been manufactured
and are proving to be viable in real-world tests on mainstream cars.
Additionally, their disposal is more eco-friendly than traditional lithium
ion batteries.
Flywheel Energy Storage works by accelerating a rotor (flywheel) to a
very high speed and maintaining the
energy in the system as rotational energy. When energy is extracted
from the system, the flywheel's rotational speed is reduced as a
consequence of the principle of conservation of energy; adding energy to
the system correspondingly results in an increase in the speed of the
flywheel. Most FES systems use electricity to accelerate and decelerate
the flywheel, but devices that directly use
mechanical energy are being
developed. Advanced FES systems have rotors made of high strength
carbon-fiber composites, suspended by
magnetic bearings, and spinning at speeds from 20,000 to over 50,000
rpm in a vacuum enclosure. Such flywheels can come up to speed in a matter
of minutes – reaching their energy capacity much more quickly than some
other forms of storage.
Batteries (mechanical
battery).
Flywheel Storage.
Rotational Energy or angular kinetic energy is
kinetic energy due to
the rotation of an object and is part of its total kinetic energy. Looking
at rotational energy separately around an object's axis of rotation, the
following dependence on the object's moment of inertia is observed.
Planck Constant is a physical constant that is the
quantum
of action, central in quantum mechanics.
Rotating
Rotation is a circular movement of an object around a center
or point of rotation. A three-dimensional object always rotates around
an imaginary line called a
rotation axis. If the axis passes through the
body's center of mass, the body is said to rotate upon itself, or spin.
Axis is the center around which something rotates.
Centrifuge -
Orbit.
Rotation Around a Fixed Axis is a special case of rotational motion.
The fixed axis hypothesis excludes the possibility of an axis changing its
orientation, and cannot describe such phenomena as
wobbling or precession.
According to Euler's rotation theorem, simultaneous rotation along a
number of stationary axes at the same time is impossible. If two rotations
are forced at the same time, a new axis of rotation will appear. This
article assumes that the rotation is also stable, such that no torque is
required to keep it going. The kinematics and dynamics of rotation around
a fixed axis of a rigid body are mathematically much simpler than those
for free rotation of a rigid body; they are entirely analogous to those of
linear motion along a single fixed direction, which is not true for free
rotation of a rigid body. The expressions for the kinetic energy of the
object, and for the forces on the parts of the object, are also simpler
for rotation around a fixed axis, than for general rotational motion. For
these reasons, rotation around a fixed axis is typically taught in
introductory physics courses after students have mastered linear motion;
the full generality of rotational motion is not usually taught in
introductory physics classes.
Tennis Racket Theorem is a result in classical mechanics describing
the movement of a rigid body with three distinct principal moments of
inertia. It is also dubbed the Dzhanibekov effect, The theorem describes
the following effect: rotation of an object around its first and third
principal axes is stable, while rotation around its second principal
axis (or intermediate axis) is not. The experiment can be performed
with any
object that has three different moments of
inertia. The effect occurs whenever the axis of rotation differs only
slightly from the object's second principal axis; air resistance or
gravity are not necessary.
The Bizarre
Behavior of Rotating Bodies, Explained (youtube) -
Magnetic Flip -
Aircraft Principal Axes.
Nutation
is a rocking,
wobbling, swaying, or nodding
motion in the axis of rotation of a largely axially symmetric object, such
as a gyroscope, planet, or bullet in flight, or as an intended behavior of
a mechanism. In an appropriate reference frame it can be defined as a
change in the second Euler angle. If it is not caused by forces external
to the body, it is called free nutation or Euler nutation. A pure nutation
is a movement of a rotational axis such that the first Euler angle is
constant. In spacecraft dynamics, precession (a change in the first Euler
angle) is sometimes referred to as nutation.
Trajectory
Trajectory is the path that a moving object follows through space as a
function of time. The object might be a projectile or a satellite.
Trajectory of a Projectile is the path that a thrown or
launched projectile or missile without propulsion will take under the
action of gravity, neglecting all other forces, such as friction from aerodynamic drag.
Torque
Torque is the tendency of a
force to rotate an object
about an axis.
Torsion in mechanics is the twisting of an object due to an applied
torque.
Torsion is expressed in newton per squared meter (Pa) or
pound per squared inch (psi) while torque is expressed in newton metres (N·m)
or foot-pound force (ft·lbf). In sections perpendicular to the torque
axis, the resultant shear stress in this section is perpendicular to the
radius.
Torsion Spring (twisting force) -
Mousetrap (wiki) -
Spring (elastic rubber) -
Tensile
Torsion
Tensor is a manner of characterizing a twist or screw
of a moving frame around a curve. The torsion of a curve, as it appears in
the Frenet–Serret formulas, for instance, quantifies the twist of a curve
about its tangent vector as the curve evolves (or rather the rotation of
the Frenet–Serret frame about the tangent vector). In the geometry of
surfaces, the geodesic torsion describes how a surface twists about a
curve on the surface. The companion notion of curvature measures how
moving frames "roll" along a curve "without twisting.
Cheetah
(image).
Vorticity is a pseudovector field that describes the local
spinning motion of a continuum
near some point (the tendency of something to rotate ), as would be seen
by an observer located at that point and traveling along with the flow.
Capillary Action (water) -
Erosion
Torsion Spring is a spring that works by twisting its end along its
axis; that is, a flexible
elastic object that stores
mechanical energy when it is twisted. When it is twisted, it exerts a
torque in the opposite direction, proportional to the amount (angle) it is
twisted. There are various types: A torsion bar is a straight bar of metal
or rubber that is subjected to twisting (shear stress) about its axis by
torque applied at its ends. A more delicate form used in sensitive
instruments, called a torsion fiber consists of a fiber of silk, glass, or
quartz under tension, that is twisted about its axis. A helical torsion
spring, is a metal rod or wire in the shape of a
helix (coil) that is subjected to twisting about the axis of the coil by
sideways forces (bending moments) applied to its ends, twisting the coil
tighter. Clocks use a spiral wound torsion spring (a form of helical
torsion spring where the coils are around each other instead of piled up)
sometimes called a "clock spring" or colloquially called a mainspring.
Those types of torsion springs are also used for attic stairs, clutches,
and other devices that need near constant torque for large angles or even
multiple revolutions.
Magnetism
Mach's Principle local inertial frames are determined by the
large scale distribution of matter, as exemplified by this anecdote: You
are standing in a field looking at the stars. Your arms are resting freely
at your side, and you see that the distant stars are not moving. Now start
spinning. The stars are whirling around you and your arms are pulled away
from your body. Why should your arms be pulled away when the stars are
whirling? Why should they be dangling freely when the stars don't move?
Mach's principle says that this is not a coincidence—that there is a
physical law that relates the motion of the distant stars to the local
inertial frame. If you see all the stars whirling around you, Mach
suggests that there is some physical law which would make it so you would
feel a centrifugal force. There are a number of rival formulations of the
principle. It is often stated in vague ways, like "mass out there
influences inertia here". A very general statement of Mach's principle is
"Local physical laws are determined by the large-scale structure of the
universe.
Ernst Mach was an Austrian physicist and philosopher, noted
for his contributions to physics such as study of shock waves. (18
February 1838 – 19 February 1916).
Ultrarelativistic Limit is when its speed is very close to
the speed of light c.
Light -
Sound -
Engineering.
Acceleration - Velocity - Speed
Acceleration is the rate of change of
velocity of an object with
respect to
time. An object's acceleration is the net result of any and all
forces acting on the object, as described by
Newton's Second Law. The SI
unit for acceleration is metre per second squared (m s−2). Accelerations
are vector quantities (they have magnitude and direction) and add
according to the parallelogram law. As a vector, the calculated net force
is equal to the product of the object's mass (a scalar quantity) and its
acceleration.
Accelerate is to cause
something to move faster.
Rockets.
Accelerometer is a device that measures proper acceleration. Proper
acceleration, being the acceleration (or rate of change of velocity) of a
body in its own instantaneous rest frame, is not the same as coordinate
acceleration, being the acceleration in a fixed coordinate system. For
example, an accelerometer at rest on the surface of the Earth will measure
an acceleration due to Earth's gravity, straight upwards (by definition)
of g ≈ 9.81 m/s2. By contrast, accelerometers in free fall (falling toward
the center of the Earth at a rate of about 9.81 m/s2) will measure zero.
Velocity
of an object is the rate of change of its position with respect to a
frame
of reference, and is a function of time. Velocity is equivalent to a
specification of its speed and direction of motion (e.g. 60 km/h to the
north).
Kinetic Energy.
Speed of
an object is the magnitude of its velocity (the rate of change of its
position); it is thus a scalar quantity. The average speed of an object in
an interval of
time is the
distance travelled by the object divided by
the duration of the interval; the instantaneous speed is the limit of the
average speed as the duration of the time interval approaches zero. Speed
has the dimensions of distance divided by time. The SI unit of speed is
the metre per second, but the most common unit of speed in everyday usage
is the kilometre per hour or, in the US and the UK, miles per hour. For
air and marine travel the knot is commonly used. The fastest possible
speed at which energy or information can travel, according to special
relativity, is the
speed of light
in a vacuum c = 299,792,458 metres per second (approximately
1,079,000,000 km/h or 671,000,000 mph). Matter cannot quite reach the
speed of light, as this would require an infinite amount of energy. In
relativity
physics, the concept of
rapidity replaces the classical idea of speed.
0-100 in less than a second. And I'm driving (youtube)
Thrust
is when a system expels or accelerates mass in one direction, the
accelerated mass will cause a force of equal magnitude but opposite
direction on that system.
Propulsion.
Cheetahs
can attain short bursts of speed well over 100 km/h (
62
mph), the American quarter horse has topped 88 km/h (55 mph),
greyhounds can reach 70 km/h (43 mph), and the Mongolian wild ass has been
measured at 64 km/h (40 mph). Even the
domestic cat
may reach 48 km/h (30 mph).
Human Running
Speed.
Terminal Velocity is the highest velocity attainable by an object as
it falls through a fluid (air is the most common example, but the concept
applies equally to any fluid).
Angular Velocity
of an object is the rate of change of its angular displacement with
respect to time. The SI unit of angular velocity is radians per second.
Angular velocity is usually represented by the symbol omega (ω, rarely Ω).
When the angular velocity is represented as a vector, its direction is
perpendicular to the plane of rotation, with its orientation
conventionally specified by the right-hand rule.
Hypersonic Speed is one that is highly
supersonic. Since the 1970s, the term has generally referred to speeds
of
Mach 5 and above. The precise Mach number at which a craft can be said
to be flying at hypersonic speed varies, since individual physical changes
in the airflow (like molecular dissociation and ionization) occur at
different speeds; these effects collectively become important around Mach
5. The hypersonic regime is often alternatively defined as speeds where
ramjets do not produce net thrust.
Rocket Engines.
Speed of Sound is the distance travelled per unit time by a
sound wave as it propagates through an
elastic medium. In dry air at 0 °C (32 °F), the speed of sound is 331.2
metres per second (1,087 ft/s; 1,192 km/h; 741 mph; 644 kn). At 20 °C (68
°F), the speed of sound is 343 metres per second (1,125 ft/s; 1,235 km/h;
767 mph; 667 kn), or a kilometre in 2.91 s or a mile in 4.69 s.
Kinematics describes the motion of points (alternatively "particles"),
bodies (objects), and systems of bodies without consideration of the
masses of those objects nor the forces that may have caused the motion.
Fermi Acceleration is the acceleration that charged
particles undergo when being repeatedly reflected, usually by a magnetic
mirror (see also Centrifugal mechanism of acceleration). This is thought
to be the primary mechanism by which particles gain non thermal energies
in astrophysical shock waves. It plays a very important role in many
astrophysical models, mainly of shocks including solar flares and
supernova remnants.
Cosmic Rays -
Atoms -
Physics Math Information
The
Quantum of action in the photon is not separated into a
separate piece of time and a separate piece of energy.
Each
ordinary (observable)
Photon in the universe consists of a little piece (quantum)
of non-observable action.
Light.
Pendulums
Pendulum
is a weight suspended from a
pivot so that it can
swing freely. When a
pendulum is displaced sideways from its resting,
equilibrium position, it
is subject to a restoring force due to gravity that will
accelerate it
back toward the equilibrium position. When released, the restoring
force
combined with the pendulum's
mass causes it to
oscillate about the
equilibrium position, swinging back and forth. The time for one complete
cycle, a left swing and a right swing, is called the
period. The period
depends on the length of the pendulum and also to a slight degree on the
amplitude, the width of the pendulum's swing.
How To Make A
Pendulum Wave (Science Experiment / Physics Toy) (youtube)
Pendulum Clock is a
clock that uses a pendulum, a swinging weight, as
its
timekeeping element. The advantage of a pendulum for
timekeeping is
that it is a harmonic oscillator: it swings back and forth in a precise
time interval dependent on its length, and resists swinging at other
rates.
Metronome (tempo) -
Synchronicity -
Principle Vibration
Harmonic Oscillator is a system that, when displaced from its
equilibrium position, experiences a restoring force F proportional to the
displacement x.
Damping
is an influence within or upon an
oscillatory system that has the effect of reducing or preventing its
oscillation. In physical
systems, damping is produced by processes that dissipate the energy stored
in the oscillation. Examples include viscous drag in mechanical systems,
resistance in electronic oscillators, and absorption and scattering of
light in optical oscillators. Damping not based on energy loss can be
important in other oscillating systems such as those that occur in
biological systems and bikes.
Spring Pendulum is a physical system where a piece of mass is
connected to a
spring so that the resulting motion
contains elements of a simple pendulum as well as a spring. The system is
much more complex than a simple pendulum, as the properties of the spring
add an extra dimension of freedom to the system. For example, when the
spring compresses, the shorter radius causes the spring to move faster due
to the conservation of angular momentum. It is also possible that the
spring has a range that is overtaken by the motion of the pendulum, making
it practically neutral to the motion of the pendulum.
Agent is a substance that exerts some force
or effect. An active and efficient cause; capable of producing a certain
effect.
Wilberforce
Pendulum consists of a mass suspended by a long helical spring and
free to turn on its vertical axis, twisting the spring. It is an example
of a coupled mechanical oscillator, often used as a demonstration in
physics education. The mass can both bob up and down on the spring, and
rotate back and forth about its vertical axis with
torsional vibrations. When correctly adjusted and set in motion, it
exhibits a curious motion in which periods of purely
rotational oscillation gradually alternate with periods of purely up
and down
oscillation. The
energy stored in the device shifts slowly back and forth between the
translational 'up and down' oscillation mode and the torsional 'clockwise
and counterclockwise' oscillation mode, until the motion eventually dies
away. Despite the name, in normal operation it does not swing back and
forth as ordinary pendulums do. The mass usually has opposing pairs of
radial 'arms' sticking out horizontally, threaded with small weights that
can be screwed in or out to adjust the moment of inertia to 'tune' the
torsional vibration period.
Coupled Oscillations is where energy alternates between two forms of
oscillation.
Motion
Motion is a
change in
position of an object with respect to
time.
Motion is typically described in terms of
displacement,
distance,
velocity,
acceleration,
time and
speed.
Motion of a body is observed by attaching a
frame of reference to an
observer and measuring the change in position of the body
relative to that
frame.
Gravity -
Chaotic Motion
-
Expansion -
Contraction -
Perpetual
Newton's 3 Laws of Motion (wiki)
First
Law:
If a body is at
rest it remains at rest or, if it is in motion, it moves
with uniform
velocity, until it is acted on by a resultant
force.
Second Law: The resultant
force is equal to
mass times
acceleration. A resultant force, also called a net force, is a
force equal to the sum of all forces applied to an object.
Materials Science.
Third Law: For every action, there is an
equal and
opposite reaction. Or every action always reacts in the opposite
direction.
One
Newton is the
force needed to accelerate one
kilogram of mass at the rate of one metre per second squared in the
direction of the applied force. The units "metre per second squared" can
be understood as change in velocity per time, i.e. an increase of velocity
by 1 metre per second every second.
Philosophiae Naturalis Principia Mathematica is a work in
three books by
Isaac
Newton, in Latin, first published 5 July 1687. After
annotating and correcting his personal copy of the first edition, Newton
published two further editions, in 1713 and 1726. The Principia states
Newton's laws of motion, forming the foundation of classical mechanics;
Newton's law of universal gravitation; and a derivation of Kepler's laws
of planetary motion (which Kepler first obtained empirically). The
Principia is considered as one of the most important works in the history
of science.
Introduction to Motion (youtube) -
Wheel Momentum by Walter Lewin (youtube)
Equations of
Motion are equations that describe the behavior of a
physical system in terms of its
motion as a
function of
time. More specifically, the equations of
motion describe the behaviour of a physical system as a set of
mathematical functions in terms of dynamic variables: normally
spatial
coordinates and time are used, but others are also possible, such as
momentum components and time. The most general choice are generalized
coordinates which can be any convenient variables characteristic of the
physical system. The functions are defined in a
Euclidean space in
classical mechanics, but are replaced by curved spaces in relativity. If
the dynamics of a system is known, the equations are the solutions to the
differential equations describing the motion of the dynamics.
Locomotion is the power or the
ability to
move or to have
self-propelled movement.
Move is to
change location and to travel or
to proceed to some place or to a new position.
Six Degrees of Freedom or six degrees of movement, refers to the six
mechanical degrees of freedom of movement of a rigid body in
three-dimensional space. Specifically, the body is free to change position
as forward/backward (surge), up/down (heave), left/right (sway)
translation in three perpendicular axes, combined with changes in
orientation through rotation about three perpendicular
axes, often termed
yaw (normal axis), pitch (transverse axis), and roll (longitudinal axis).
Walking (or surging): Moving forward and
backward; Strafing (or swaying): Moving left and right; Elevating
(or heaving): Moving up and down; Roll
Rotation:
Pivots side to side; Pitch Rotation: Tilts forward
and backward; Yaw Rotation: Swivels left and right.
Ship Motions
(wiki) -
Aircraft Flight -
Planets -
Atoms
Three Degrees of Freedom is a term often used in the context of
virtual reality, typically refers to
tracking of rotational motion only: pitch, yaw, and roll. There are the
three degrees of freedom in a straight line, left, right, up, down,
forwards and backwards, but things can also rotate or spin. One end of a
spacecraft can rotate up or down with respect to the other end, this is
known as pitch and can cause the spacecraft to spin like a cartwheel. (x y
z).
Degrees of Freedom of a mechanical system is the number of independent
parameters that define its configuration or state. The position of a
single railcar (engine) moving along a track has one degree of freedom
because the position of the car is defined by the distance along the
track. A train of rigid cars connected by hinges to an engine still has
only one degree of freedom because the positions of the cars behind the
engine are constrained by the shape of the track. An automobile with
highly stiff suspension can be considered to be a rigid body traveling on
a plane (a flat, two-dimensional space). This body has three independent
degrees of freedom consisting of two components of translation and one
angle of rotation. Skidding or drifting is a good example of an
automobile's three independent degrees of freedom. The position and
orientation of a rigid body in space is defined by three components of
translation and three components of rotation, which means that it has six
degrees of freedom.
The exact constraint mechanical design method
manages the degrees of freedom to neither underconstrain nor overconstrain
a device.
Degrees of Freedom Problem or motor equivalence problem states that
there are multiple ways for humans or animals to perform a movement in
order to achieve the same goal. In other words, under normal
circumstances, no simple one-to-one correspondence exists between a
motor problem or task and a motor solution to
the problem.
Geometric Terms of Location describe
directions or positions relative to the shape of an object. These
terms are used in descriptions of engineering, physics, and other
sciences, as well as ordinary day-to-day discourse.
Three-dimensional beings such as humans with a 2D retina, can see all the
sides and the insides of a 2D shape simultaneously, a 4D being could see
all faces and the inside of a 3D shape at once with their 3D retina.
Reaction
states that all
forces occur in pairs such that if one object exerts a
force on another object, then the second object exerts an equal and
opposite reaction force on the first. The third law is also more generally
stated as: "
To every action there is always opposed an equal reaction: or
the mutual actions of two bodies upon each other are always equal, and
directed to contrary parts." The attribution of which of the two forces is
the action and which is the
reaction is arbitrary. Either of the two can
be considered the
action, while the other is its associated reaction.
Body Motion -
Activism
7 Myths About
Movement (youtube)
Displacement is a vector that is the shortest
distance from the initial to the
final position of a point P. It quantifies both the distance and direction
of an imaginary motion along a straight line from the initial position to
the final position of the point. A displacement may be also described as a
'relative position': the final position of a point (Sf) relative to its
initial position (Si), and a displacement vector can be mathematically
defined as the difference between the final and initial position vectors.
Mechanics
is an area of science concerned with the behavior of physical bodies when
subjected to forces or displacements, and the subsequent effects of the
bodies on their environment.
Mechanics
is the branch of physics concerned with the motion of bodies in a frame of
reference. The technical aspects of doing something.
Quantum Mechanics
Dynamics in mechanics is a branch of applied mathematics (specifically
classical mechanics) concerned with the study of
forces
and torques and their effect on motion, as opposed to kinematics, which
studies the motion of objects without reference to its causes. Isaac
Newton defined the fundamental physical laws which govern dynamics in
physics, especially his second law of motion.
Materials Science.
Dynamics is the branch of mechanics concerned with the forces that
cause motions of bodies.
Vehicular Dynamics refers to the dynamics of
vehicles, here assumed to be ground vehicles. Vehicle dynamics is a part
of engineering primarily based on
classical mechanics.
Ricochet
is to spring back or spring
away from an impact.
Rebound is a movement
back from an impact.
Bounce is to move up and
down repeatedly.
Deflection is to turn
away from a
straight course, or fixed direction, or line of interest. Turn aside and away
from an initial or intended course.
Locomotion is the power or the ability to move. Self-propelled
movement.
Space
Travel (rockets) -
Work
in relation to
physics, is
when acting there is a displacement of the point of application in the
direction of the
force. For example, when a ball is held above the ground
and then dropped, the
work done on the ball as it falls is equal to the
weight of the ball (a force) multiplied by the distance to the ground (a
displacement).
Power
in relation
to
physics, is the rate of doing
work.
Work
in relation to
electrical, is the
work done on a charged particle by an electric
field. The equation for
electrical work is equivalent to that of
'mechanical' work.
Energy -
Machines.
Potential
Potentiality and
actuality is a
change or
activity that represents the
possibility of something happening. The inherent
capacity for coming into
being. A possibility becomes real when knowledge of the
requirements that
are
needed to complete a task are available. Not to say something will
happen, it's saying that something
could happen under the
right
conditions or requirements.
Potential is possessing numerous
possibilities. The capacity for
coming into being. Having
prospect and the possibility of future
success. Having
capability and
aptitude that may be
developed. Having the skills and
qualifications
to do things well.
Action-Specific Perception is when people perceive their
environment and events within it in terms of their
ability to act.
Self-Fulfillment is the
realizing of one's deepest desires and
capacities. A satisfying and
worthwhile
life well lived.
Evoked Potential
is an electrical potential recorded from the
nervous system of a
human or other animal following
presentation of a
stimulus, as distinct from spontaneous
potentials as detected by
electroencephalography (EEG), electromyography (EMG), or other
electrophysiologic recording method. Such potentials are useful for
electrodiagnosis and monitoring.
Speed Reading.
Long-Term Potentiation is a persistent strengthening of
synapses based on recent
patterns of activity. These are patterns of synaptic activity that produce
a long-lasting increase in
signal transmission between two neurons. The
opposite of LTP is
long-term depression, which produces a long-lasting decrease in
synaptic strength. It is one of several phenomena underlying
synaptic plasticity, the
ability of chemical synapses to change their strength. As
memories are thought to be encoded
by modification of synaptic strength, LTP is widely considered one of the
major cellular mechanisms that underlies
learning and memory.
Depotentiation is when the long term
potentiation has been erased. The action of a substance that reduces the
effect of another substance.
Deficiencies.
Action Potential
is a short-lasting event in which the
electrical membrane potential of a
cell rapidly rises and falls, following a consistent trajectory.
Resting Potential of quiescent
cells
is called the resting membrane potential or resting voltage, as opposed to
the specific dynamic electrochemical phenomena called action potential and
graded membrane potential. Apart from the latter two, which occur in
excitable cells (neurons, muscles, and some secretory cells in glands),
membrane voltage in the majority of non-excitable cells can also undergo
changes in response to environmental or intracellular stimuli. The resting
potential exists due to the differences in membrane
permeabilities for
potassium, sodium, calcium, and chloride ions, which in turn result from
functional activity of various ion channels, ion transporters, and
exchangers. Conventionally, resting membrane potential can be defined as a
relatively stable, ground value of transmembrane voltage in animal and
plant cells. The typical resting membrane potential of a cell arises from
the separation of
potassium ions from
intracellular, relatively immobile anions across the membrane of the cell.
Because the membrane permeability for potassium is much higher than that
for other ions, and because of the strong chemical gradient for potassium,
potassium ions flow from the cytosol into the extracellular space carrying
out positive charge, until their movement is balanced by build-up of
negative charge on the inner surface of the membrane. Again, because of
the high relative permeability for potassium, the resulting membrane
potential is almost always close to the potassium reversal potential. But
in order for this process to occur, a concentration gradient of potassium
ions must first be set up. This work is done by the ion pumps/transporters
and/or exchangers and generally is powered by
ATP. In the case of the
resting membrane potential across an animal cell's plasma membrane,
potassium (and sodium) gradients are established by the Na+/K+-ATPase
(sodium-potassium pump) which transports 2 potassium ions inside and 3
sodium ions outside at the cost of 1 ATP molecule. In other cases, for
example, a membrane potential may be established by acidification of the
inside of a membranous compartment (such as the
proton pump that generates
membrane potential across synaptic vesicle membranes).
Membrane
Potential is the difference in electric potential between the interior
and the exterior of a
biological cell. With respect to the exterior of the
cell, typical values of membrane potential range from –40 mV to –80 mV.
Porous.
Electric
Potential is the amount of electric potential
energy that a unitary
point
electric charge would have if located at any point in space, and is
equal to the work done by an external agent in carrying a unit of positive
charge from the arbitrarily chosen reference point (usually infinity) to
that point without any acceleration.
Natures Electrical Properties.
Electric
Potential Energy is a potential energy (measured in joules) that
results from conservative Coulomb forces and is associated with the
configuration of a particular set of point charges within a defined
system.
Potential Energy
is energy possessed by a body by virtue of its position relative to
others, stresses within itself, electric charge, and other factors.
Batteries -
Electric Potential Difference (voltage).
Yukawa Potential is the amplitude of potential, m is the
mass of the particle, r is the
radial distance to the particle, and k is another scaling constant, so
that 1/km is the range. The potential is monotone increasing in r and it
is negative, implying the force is attractive. In the SI system, the unit
of the Yukawa potential is (1/m).
Multipotentiality is an educational and psychological term
referring to the ability and preference of a person, particularly one of
strong intellectual or
artistic curiosity, to
excel in two or more different
fields. It can also refer to an individual whose interests span
multiple fields or areas, rather than being strong in just one. Such
traits are called multipotentialities, while "multipotentialites" has been
suggested as a name for those with this trait. By contrast, those whose
interests lie
mostly within a single field are called "
specialists."
Potential Well is the region surrounding a local minimum of potential
energy. Energy captured in a potential well is unable to convert to
another type of energy (
kinetic
energy in the case of a gravitational potential well) because it is
captured in the local minimum of a potential well. Therefore, a body may
not proceed to the global minimum of potential energy, as it would
naturally tend to due to
entropy.
Threshold
Potential is the critical level to which a membrane potential must be
depolarized to initiate an action potential. Threshold potentials are
necessary to regulate and propagate signaling in both the
central nervous system
(CNS) and the peripheral nervous system (PNS).
Thermodynamics.
Untapped is something that has not
yet been fully
utilized or used, or taken advantage of
some gift.
Information Potential.
Unlocking Potential is to free or release
oneself from restraints, restrictions or doubts.
Probability (odds)
Opportunity is a
favorable combination of circumstances
that makes it
possible to do something advantageous or
beneficial for a particular
purpose. A
chance for making
progress and
achieving a
goal.
Window of Opportunity is a period of time during which some action can
be taken that will achieve a desired outcome. Once this period is over, or
the "window is closed", the specified outcome is no longer possible.
Launch Window.
Opportunistic is exploiting
chances offered by immediate
circumstances without reference to a general plan or moral principle.
Opportunistic of a plant or animal is being able to spread quickly in a
previously unexploited habitat.
Adapt.
Opportunity Cost is the
cost that is incurred by not
utilizing a
benefit from an option that was chosen from alternatives.
Elastics - Bouncing Back
Elasticity in physics is the ability of a body to resist a distorting
influence or deforming force and to
return to its original size and shape
when that influence or force is removed. Solid objects will deform when
adequate forces are applied on them. If the material is
Elastic, the object will return to its initial shape and size when
these forces are removed.
The physical reasons for elastic behavior can be quite different for
different materials. In
metals, the
atomic lattice changes size and shape
when forces are applied (energy is added to the system). When forces are
removed, the lattice goes back to the original lower energy state. For
rubbers and other polymers, elasticity is caused by the stretching of
polymer chains when forces are applied.
Elastic is something capable of
resuming original shape after
stretching or
compression; Springy. Able to
adjust readily to different conditions.
Resilience -
Adaptable -
Surface Tension
-
Tensile Strength -
Kinetic Energy -
Muscles -
Stretching
Silicone Rubber is an elastomer (rubber-like material) composed of
silicone—itself a polymer—containing silicon together with carbon,
hydrogen, and oxygen.
Rubber
Band is a loop of
Rubber,
usually ring shaped, and commonly used to hold multiple objects together.
The rubber band was patented in England on March 17, 1845, by Stephen
Perry. Most rubber bands are manufactured out of natural rubber or,
especially at larger sizes, elastomer, and are sold in a variety of sizes.
Visco-Elastic Material absorbs,
isolates, and reduces vibrations simultaneously. It is capable of
absorbing nearly 95% of shock energy and reducing more than 50% of
vibration energy. Sorbothane performs well in nearly every industrial
application.
Rubber hardens over time. Natural rubber degrades and hardens
as heat, oils, and even simple oxygen cause chemical reactions. Therefore,
limiting exposure to heat, oils, and oxygen is one way to delay the
hardening of rubber objects. At the same time, however, properly employed
heat or oil can restore some softness to rubber objects, although it is a
battle that will eventually be lost. Placing rubber items in zip-close
bags and using a straw to suck out most of the air can noticeably delay
the hardening process. Heat the rubber with a blow dryer may help, but
there are many rubber formulations, and some may respond better than
others. Also, there is no miracle cure, and some hardened rubber items
will simply be too far gone for softening. You are actually damaging the
rubber by heating it to soften it, and some items cannot take the beating
any longer.
Viscoelasticity is the property of materials that exhibit both
viscous and elastic
characteristics when undergoing deformation. Viscous materials, like
water, resist shear flow and strain linearly with time when a stress is
applied. Elastic materials strain when stretched and immediately return to
their original state once the stress is removed. Viscoelastic materials
have elements of both of these properties and, as such, exhibit
time-dependent strain. Whereas elasticity is usually the result of bond
stretching along crystallographic planes in an ordered solid, viscosity is
the result of the diffusion of atoms or molecules inside an amorphous
material.
Inelastic Collision is a collision in which
kinetic energy is not
conserved due to the action of internal friction. In collisions of
macroscopic bodies, some kinetic energy is turned into vibrational energy
of the atoms, causing a heating effect, and the bodies are deformed.
Elastic Collision is an encounter between two bodies in which the
total
kinetic energy of the
two bodies remains the same. In an ideal, perfectly elastic collision,
there is no net conversion of kinetic energy into other forms such as
heat, noise, or potential energy.
Rubber Dampers or shock
absorbers are used to reduce the transmission of shock to the surrounding
structure. Shock absorption is possible as the rubber absorber deflects
under the applied shock load. The construction of rubber dampers (also
known as rectangular buffers) is such that rubber is bonded to a metal
plate which incorporates a number of fixing holes allowing for simple
installation. A wide range of dimensions and rubber hardness options are
available from stock or alternatively rectangular buffers and rubber
dampers can be specially manufactured to meet the customer's individual
requirement.
Slowmo Comparison between 2 gimbals on simple shake table Left: Newer
stiffer rubber dampers (youtube).
Shock Absorber
is a mechanical or hydraulic device designed to absorb and damp shock
impulses. It does this by converting the kinetic energy of the shock into
another form of energy (typically heat) which is then dissipated. Most
shock absorbers are a form of dashpot (a damper which resists motion via
viscous
friction).
Vibration
Isolation is the process of isolating an object, such as a piece of
equipment, from the source of vibrations.
Vibration is a
mechanical phenomenon whereby oscillations occur about an equilibrium
point. The word comes from Latin vibrationem ("shaking, brandishing"). The
oscillations may be periodic, such as the
motion of
a
pendulum—or random, such as the movement of a
tire on a gravel road. The studies of
sound and vibration are closely
related. Sound, or
pressure waves, are
generated by vibrating structures (e.g. vocal cords); these pressure waves
can also induce the vibration of structures (e.g. ear drum). Hence,
attempts to reduce noise are often related to issues of vibration.
Ball Joint are
spherical bearings that connect the control arms to the steering knuckles.
They are used on virtually every automobile made and work similarly to the
ball-and-socket design of the
human hip joint or
Synovial Joint,
which joins bones with a fibrous joint capsule that is continuous with the
periosteum of the joined bones, constitutes the outer boundary of a
synovial cavity, and surrounds the bones' articulating surfaces. The
synovial cavity/joint is filled with synovial fluid. The
joint capsule is made up of an outer layer, the articular capsule,
which keeps the bones together structurally, and an inner layer, the
synovial membrane, which seals in the synovial fluid. They are the most
common and most movable type of joint in the body of a mammal. As with
most other joints, synovial joints achieve movement at the point of
contact of the articulating bones. (lso known as diarthrosis).
Resilin is
an elastomeric protein found in many insects and arthropods. It provides
soft rubber-elasticity to mechanically active organs and tissue; for
example, it enables insects of many species to jump or pivot their wings
efficiently. Resilin was first discovered by Torkel Weis-Fogh in locust
wing-hinges. Resilin is currently the most efficient elastic protein known
(Elvin et al., 2005). The elastic efficiency of the resilin isolated from
locust tendon has been reported to be 97% (only 3% of stored energy is
lost as heat). It does not have any regular structure but its randomly
coiled chains are crosslinked by di- and tri-tyrosine links at the right
spacing to confer the elasticity needed to propel some jumping insects
distances up to 38 times their length (as found in fleas). Resilin must
last for the lifetime of adult insects and must therefore operate for
hundreds of millions of extensions and contractions; its elastic
efficiency ensures performance during the insect's lifetime. Resilin
exhibits unusual elastomeric behavior only when swollen in polar solvents
such as water.
Rubber that doesn't grow cracks when stretched many times. Researchers
have increased the fatigue threshold of particle-reinforced rubber,
developing a new, multiscale approach that allows the material to bear
high loads and resist crack growth over repeated use. This approach could
not only increase the longevity of rubber products such as tires but also
reduce the amount of pollution from rubber particles shed during use.
Fleas can
jump 38 times their body length (jump speed is one thousandth of a
second).
Frogs can jump 20 times their body length.
Jumping Spiders can jump 100 times their body length. At the 1968
Summer Olympics Bob Beamon jumped 8.90 m (29 ft 2 1⁄4 in) at an altitude
of 7,349 feet (2,240 m), a
jump
not exceeded for 23 years, and which remains the second longest legal jump
of all time.
Jump is to
push oneself off a
surface and into the air by using the
muscles in the legs and feet.
Gravity.
Elastomer is a
polymer
with viscoelasticity (i. e., both viscosity and elasticity) and very weak
inter-molecular forces, and generally low Young's modulus and high failure
strain compared with other
materials. The term, a portmanteau of elastic polymer, is often used
interchangeably with rubber, although the latter is preferred when
referring to vulcanisates. Each of the monomers which link to form the
polymer is usually a compound of several elements among carbon, hydrogen,
oxygen and silicon. Elastomers are amorphous polymers maintained above
their glass transition temperature, so that considerable molecular
reconformation, without breaking of covalent bonds, is feasible. At
ambient temperatures, such rubbers are thus relatively soft (E ≈ 3 MPa)
and deformable. Their primary uses are for seals, adhesives and molded
flexible parts. Application areas for different types of rubber are
manifold and cover segments as diverse as tires, soles for shoes, and
damping and insulating elements. The importance of these rubbers can be
judged from the fact that global revenues are forecast to rise to
US$56 billion in 2020. IUPAC defines the term "elastomer" by "Polymer that
displays rubber-like elasticity." Rubber-like solids with elastic
properties are called elastomers. Polymer chains are held together in
these materials by relatively weak intermolecular bonds, which permit the
polymers to stretch in response to macroscopic stresses. Natural rubber,
neoprene rubber, buna-s and buna-n are all examples of such elastomers.
Catapult is a device in which accumulated
tension is suddenly released to hurl an object some distance, in
particular.
Spring as a device is an elastic object that stores mechanical energy.
Springs are typically made of spring steel. There are many spring designs.
In everyday use, the term often refers to coil springs. When a
conventional spring, without stiffness variability features, is compressed
or stretched from its resting position, it exerts an opposing force
approximately proportional to its change in length (this approximation
breaks down for larger deflections). The rate or spring constant of a
spring is the change in the force it exerts, divided by the change in
deflection of the spring. That is, it is the
gradient of the force
versus deflection curve. An extension or
compression spring's rate is
expressed in units of force divided by distance, for example lbf/in or
N/m. A
torsion spring is a spring that works by twisting; when it is
twisted about its axis by an angle, it produces a torque proportional to
the angle. A torsion spring's rate is in units of torque divided by angle,
such as N·m/rad or ft·lbf/degree. The inverse of spring rate is
compliance, that is: if a spring has a rate of 10 N/mm, it has a
compliance of 0.1 mm/N. The stiffness (or rate) of springs in parallel is
additive, as is the compliance of springs in series. Springs are made from
a variety of elastic materials, the most common being spring steel. Small
springs can be wound from pre-hardened stock, while larger ones are made
from annealed steel and hardened after fabrication. Some non-ferrous
metals are also used including phosphor bronze and titanium for parts
requiring corrosion resistance and beryllium copper for springs carrying
electrical current (because of its low electrical resistance).
Coil Spring is a
mechanical device which is typically used to store energy and subsequently
release it, to absorb shock, or to maintain a force between contacting
surfaces. They are made of an elastic material formed into the shape of a
helix which returns to its natural length when unloaded. Under tension or
compression, the material (wire) of a coil spring undergoes torsion. The
spring characteristics therefore depend on the
shear modulus, not
Young's Modulus. A coil spring may also be used as
a torsion spring: in this case the spring as a whole is subjected to
torsion about its helical axis. The material of the spring is thereby
subjected to a bending moment, either reducing or increasing the helical
radius. In this mode, it is the Young's Modulus of the material that
determines the spring characteristics. Metal coil springs are made by
winding a wire around a shaped former - a cylinder is used to form
cylindrical coil springs.
Spirals -
Waves
Recoil
is the rearward thrust generated when a gun is being discharged. In
technical terms, the recoil is a result of conservation of
momentum, as according to
Newton's third law the force required to accelerate something will
evoke an equal but opposite reactional force, which means the forward
momentum gained by the projectile and exhaust gases (ejectae) will be
mathematically balanced out by an equal and opposite momentum exerted back
upon the gun. Recoil is also called knockback, kickback or simply kick.
Slinky
is a precompressed
helical spring toy invented by Richard James in the
early 1940s. It can perform a number of tricks, including travelling down
a flight of steps end-over-end as it stretches and re-forms itself with
the aid of gravity and its own
momentum, or appear to levitate for a
period of time after it has been dropped. In the state of equilibrium of a
slinky, all net force is cancelled throughout the entire slinky. This
results in a stationary slinky with zero velocity. As the positions of
each part of the slinky is governed by the slinky's mass, the force of
gravity and the spring constant, various other properties of the slinky
may be induced.
Amazing Slinky Tricks (youtube).
Simple Harmonic Motion is a special type of periodic motion or
oscillation where the restoring force is directly proportional to the
displacement and acts in the direction opposite to that of displacement.
Somersaulting simulation for jumping bots. New simulation methods
enable easier, faster design of elastic materials for robots and other
dynamic objects.
Conservative
Force is a force with the property that the work done in moving a
particle between two points is independent of the taken path.
Equivalently, if a particle travels in a closed loop, the net work done
(the sum of the force acting along the path multiplied by the distance
travelled) by a conservative force is zero.
Coulomb's Law
is a law of physics that describes force interacting between static
electrically charged particles.
Kinetic
-
Thermoelectric
Synthetic gelatin-like material mimics lobster underbelly's stretch and
strength. Researchers fabricated a synthetic hydrogel that mimics the
stretch and strength of a lobster's underbelly. The material could provide
a blueprint for stretchy protective fabrics and artificial tissues.
Physics of Tennis
(PDF)
Dancing
T-Handle in Zero-G, HD, free floating rotation showing a
bi-stable state due to intermediate moments of inertia (youtube)
How to imitate natural spring-loaded snapping movement without losing
energy.
Venus flytraps do it, trap-jaw ants do it, and now materials
scientists can do it, too - they discovered a way of efficiently
converting
elastic energy in a spring to
kinetic energy for
high-acceleration, extreme velocity movements as nature does it.
Flight - Science of Flying
Flight
is the process by which an object moves through an
atmosphere or through the air
surrounding earth, or beyond the atmosphere into outer space such as
spaceflight, without
direct support from any surface. This can be achieved by generating
aerodynamic lift, propulsive
thrust, aerostatically using buoyancy, or by
ballistic movement.
Aviation
refers to the activities surrounding mechanical flight and the aircraft
industry. Aircraft
includes fixed-wing and rotary-wing types, morphable wings, wing-less
lifting bodies, as well as lighter-than-air craft such as balloons and
airships.
Aeronautics is the theory
and practice of
navigation through air or
space.
Aeronautics is the
science or art involved with the study, design, and manufacturing of air
flight–capable machines, and the techniques of operating aircraft and
rockets within the atmosphere. The British Royal Aeronautical Society
identifies the aspects of "aeronautical art,
science and
engineering" and "the
profession of Aeronautics (which expression includes Astronautics).
Pilot is someone who is licensed to
operate an aircraft in flight. To act as the
navigator in a car, plane, or vessel and plan, direct, plot the path
and position of the conveyance. A person qualified to guide ships through
difficult waters going into or out of a harbor.
Aircraft Pilot or
Aviator is a person
who controls the flight of an aircraft by operating its directional flight
controls. Some other aircrew members, such as
navigators or flight
engineers, are also considered aviators, because they are involved in
operating the aircraft's navigation and engine systems. Other aircrew
members, such as
drone operators, flight attendants, mechanics and ground
crew, are not classified as aviators.
Test
Pilot is an aircraft pilot with additional training to fly and
evaluate experimental, newly produced and modified aircraft with specific
maneuvers, known as flight test techniques.
Astronaut.
Air
Travel is a form of
travel in vehicles such as helicopters, hot air
balloons, blimps, gliders, hang gliding, parachuting, airplanes, jets, or
anything else that can sustain flight. Use of air travel has greatly
increased in recent decades – worldwide it doubled between the mid-1980s
and the year 2000.
Transportation.
Aircraft is a vehicle that can fly.
Aircraft is a vehicle
or machine that is able to fly by gaining support from the air. It
counters the force of gravity by using either static lift or by using the
dynamic lift of an airfoil, or in a few cases the downward thrust from jet
engines. Common examples of aircraft include airplanes, helicopters,
airships (including blimps), gliders, paramotors, and hot air balloons.
The human activity that surrounds aircraft is called aviation. The science
of aviation, including designing and building aircraft, is called
aeronautics. Crewed aircraft are flown by an onboard pilot, but unmanned
aerial vehicles may be remotely controlled or self-controlled by onboard
computers. Aircraft may be classified by different criteria, such as lift
type, aircraft propulsion, usage and others.
Fixed-Wing Aircraft is a flying machine, such as an airplane (or
aeroplane; see spelling differences), which is capable of flight using
wings that generate lift caused by the aircraft's forward airspeed and the
shape of the wings. Fixed-wing aircraft are distinct from rotary-wing
aircraft (in which the wings form a rotor mounted on a spinning shaft or
"mast"), and ornithopters (in which the wings flap in a manner similar to
that of a bird). The wings of a fixed-wing aircraft are not necessarily
rigid; kites, hang gliders, variable-sweep wing aircraft and airplanes
that use wing morphing are all examples of fixed-wing aircraft. Gliding
fixed-wing aircraft, including free-flying gliders of various kinds and
tethered kites, can use moving air to gain altitude. Powered fixed-wing
aircraft (airplanes) that gain forward thrust from an engine include
powered paragliders, powered hang gliders and some ground effect vehicles.
Most fixed-wing aircraft are flown by a pilot on board the craft, but some
are specifically designed to be unmanned and controlled either remotely or
autonomously (using onboard computers).
Airplane
is a powered, fixed-wing aircraft that is propelled forward by thrust from
a jet engine or propeller. Airplanes come in a variety of sizes, shapes,
and wing configurations.
Supply Chain.
How Planes Work -
The Science Behind Airplanes
HOW AIRPLANES FLY -
The Science Behind Flight (youtube)
Jet
Aircraft is an aircraft or
fixed-wing aircraft
that is propelled by
jet engines
or jet propulsion.
Dynamics of Flight -
Principles of Flight -
Dynamics of Space Flight - NASA -
Flight Dynamics
(spacecraft) -
Rockets (space travel) -
Flight Dynamics
(wiki) -
6 Degrees of Motion
Flight
Envelope of an
aircraft refers to the capabilities of a
design in terms of airspeed and load factor or altitude.
Propulsion is
the action or process of pushing or pulling to drive an object forward. A
propulsion system consists of a source of
mechanical power, and a propulsor
(means of converting this power into propulsive force). A technological
system uses an engine or
motor
as the power source (commonly called a powerplant), and wheels and axles,
propellers, or a propulsive nozzle to generate the force. Components such
as clutches or gearboxes may be needed to connect the motor to axles,
wheels, or propellers. propulsion system is a machine that produces thrust
to push an object forward. First, the thrust from the propulsion system
must balance the drag of the airplane when the airplane is cruising. And
second, the
thrust from the propulsion system must exceed the drag of the
airplane for the airplane to accelerate.
Jet Propulsion (rockets).
Propeller is a type of
fan that transmits
power by converting
rotational motion into thrust. A
pressure difference is produced between the forward and rear surfaces
of the airfoil-shaped blade, and a fluid (such as air or water) is
accelerated behind the blade. Propeller dynamics, like those of aircraft
wings, can be modelled by Bernoulli's principle and Newton's third law.
Most marine propellers are screw propellers with fixed helical blades
rotating around a horizontal (or nearly horizontal) axis or propeller
shaft.
Fans.
Aerodynamics
is a branch of
fluid dynamics concerned with studying the
motion of air, particularly
when it interacts with a solid object, such as an airplane wing.
Aerodynamics is a sub-field of fluid dynamics and
gas dynamics, and many aspects of aerodynamics theory are common to
these fields. The term aerodynamics is often used synonymously with gas
dynamics, with the difference being that "gas dynamics" applies to the
study of the motion of all
gases, not limited to air.
Fluid Mechanics.
Bernoulli's Principle states that an increase in the speed of a fluid
occurs simultaneously with a decrease in pressure or a decrease in the
fluid's potential energy. If the air flowing past the top surface of an
aircraft wing is moving faster than the air flowing past the bottom
surface, then Bernoulli's principle implies that the pressure on the
surfaces of the wing will be lower above than below. This pressure
difference results in an upwards lifting force.
Wing is a
type of fin that produces
lift,
while moving through air or some other fluid. As such,
wings have streamlined cross-sections that are
subject to aerodynamic forces and act as
airfoils.
A wing's aerodynamic efficiency is expressed as its lift-to-drag ratio.
The lift a wing generates at a given
speed and
angle of attack can be one to two orders of magnitude greater than the
total drag on the wing. A high
lift-to-drag ratio requires a significantly
smaller thrust to propel the wings through the air at sufficient lift.
Lifting structures used in water, include various foils, such as
hydrofoils. Hydrodynamics is the governing science, rather than
aerodynamics. Applications of underwater foils occur in hydroplanes,
sailboats and submarines. Air moves more quickly over the curved upper
surface of the wing than it does under the wing, which has a flatter
surface. The faster moving air
produces less pressure
than the slower moving air, causing the wing to l
ift
toward the area of low pressure, thus creating lift. If you turned a
wing upside down it would have the opposite effect and push down, like
with
racecar airfoils. An automotive wing is a device whose intended design
is to generate downforce as air passes around it, not simply disrupt
existing airflow patterns. As such, rather than decreasing drag,
automotive wings actually increase drag.
Spoiler is an
automotive aerodynamic device whose intended design function is to
'spoil' unfavorable air movement across a body of a vehicle in motion,
usually described as turbulence or
drag.
Spoilers on the front of a vehicle are often called air dams. Spoilers are
often fitted to race and high-performance sports cars.
Vortex Shedding -
Pressure Changes
Dragonfly wings used to study relationship between corrugated wing
structure and vortex motions. Corrugated wings exhibit larger lift than
flat wings.
Tubercle Effect is a phenomenon where tubercles or large 'bumps' on
the leading edge of an airfoil can improve its aerodynamics.
Tubercles
on humpback whales are located on the leading edge of the flippers. The
tubercles allow the very large whales to execute tight turns underwater
and swim efficiently; a task imperative for the humpback whales feeding.
Archer's Paradox refers to the phenomenon of an arrow
traveling in the direction it is pointed at full draw, when it seems that
the arrow would have to pass through the starting position it was in
before being drawn, where it was pointed to the side of the target.
Aircraft Flight Control System consists of flight control surfaces,
the respective cockpit
controls, connecting linkages, and the necessary operating mechanisms
to control an aircraft's direction in flight. Aircraft engine controls are
also considered as flight controls as they change speed. The fundamentals
of aircraft controls are explained in flight dynamics.
Bridge (ship controls).
Flight
Instruments are the instruments in the cockpit of an aircraft that
provide the pilot with information about the flight situation of that
aircraft, such as
altitude,
airspeed and
direction. They improve
safety by allowing the pilot to fly the aircraft in level flight, and make
turns, without a reference outside the aircraft such as the horizon.
Visual Flight Rules or
VFR require an airspeed indicator, an
altimeter,
and a compass or other suitable magnetic direction indicator.
Instrument Flight Rules or
IFR additionally require a gyroscopic
pitch-bank (artificial horizon), direction
(directional gyro) and rate of turn indicator, plus a slip-skid indicator,
adjustable altimeter, and a clock. Flight into Instrument meteorological
conditions or IMC require radio
navigation instruments for precise takeoffs
and landings.
Spatial Intelligence
-
Dizziness -
Pilot Error
Airway or air route, or
flight path, or
air corridor, is a defined corridor that connects one specified location
to another at a specified altitude, along which an aircraft that meets the
requirements of the airway may be flown high Airways are defined with
segments within a specific altitude block, corridor width, and between
fixed geographic coordinates for satellites navigation system, or between
ground-based Radio transmitter navigational aids (navaids; such as VORs or
NDBs) or the intersection of specific radials of two navaids.
Geodesic
relates to the
shortest possible line between two
points on a sphere or other
curved surface. Geodesic is commonly a curve representing in some
sense the shortest[a] path (arc) between two points in a surface, or more
generally in a
Riemannian manifold. The term also has meaning in any differentiable
manifold with a connection.
It is a generalization of the notion of a "straight line" to a more
general setting.
Geodesics in general relativity generalizes the notion of a "
straight
line" to
curved space time.
Importantly, the world line of a particle free from all external,
non-gravitational forces is a particular type of geodesic. In other words,
a freely moving or falling particle always moves along a geodesic. In
general relativity, gravity can be regarded as not a force but a
consequence of a curved spacetime geometry where the source of curvature
is the stress–energy tensor (representing matter, for instance). Thus, for
example, the path of a planet orbiting a star is the projection of a
geodesic of the curved four-dimensional (4-D) spacetime geometry around
the star onto three-dimensional (3-D) space.
Geodesic
Curvature (wiki).
Time of Flight is a property of an object, particle or
acoustic,
electromagnetic or other
wave. It is the time that such an object needs to
travel a distance through a medium. The measurement of this time (i.e. the
time of flight) can be used for a time standard (such as an atomic
fountain), as a way to measure
velocity or path length through a given
medium, or as a way to learn about the particle or medium (such as
composition or flow rate). The traveling object may be detected directly
(e.g., ion detector in mass spectrometry) or indirectly (e.g., light
scattered from an object in laser doppler velocimetry).
Why Are Airplane
Wings Angled Backwards?? (youtube)
Aerodynamic Force is exerted on a body by the air (or some other gas)
in which the body is immersed, and is due to the relative motion between
the body and the gas. Aerodynamic force arises from two causes: the normal
force due to the pressure on the surface of the body. The shear force due
to the viscosity of the gas, also known as skin friction. Pressure acts
locally, normal to the surface, and shear force acts locally, parallel to
the surface. The net aerodynamic force over the body is due to the
pressure and shear forces integrated over the total exposed area of the
body. When an airfoil (or a wing) is moving relative to the air it
generates an aerodynamic force, in a rearward direction at an angle with
the direction of relative motion. This aerodynamic force is commonly
resolved into two components.
Drafting in aerodynamics or slipstreaming, is a technique where two
vehicles or other moving objects are caused to align in a close group
reducing the overall effect of drag due to exploiting the lead object's
slipstream. Especially when high speeds are involved, as in motor racing
and cycling, drafting can significantly reduce the paceline's average
energy expenditure required to maintain a certain speed and can also
slightly reduce the energy expenditure of the lead vehicle or object.
Air
Flow is the movement of air from one area to another. The primary
cause of airflow is the existence of pressure gradients. Air behaves in a
fluid manner, meaning particles naturally flow from areas of higher
pressure to those where the pressure is lower. Atmospheric air pressure is
directly related to altitude, temperature, and composition. In
engineering, airflow is a measurement of the amount of air per unit of
time that flows through a particular device. The flow of air can be
induced through mechanical means (such as by operating an electric or
manual fan) or can take place passively, as a function of pressure
differentials present in the environment.
Flow Rate (water,
liquid).
Air
Flow Meter is a device that measures air flow, i.e. how much air is
flowing through a tube. It does not measure the volume of the air passing
through the tube, it measures the mass of air flowing through the device
per unit time. Thus air flow meters are simply an application of mass flow
meters for a special medium. Typically, mass air flow measurements are
expressed in the units of kilograms per second (kg/s).
Air Tightness.
Vortex is a region in a fluid in which the flow is rotating around an
axis line, which may be straight or curved.
Torus -
Vortex Shedding.
Impeller
is a
Rotor used to increase or decrease in case of turbines the pressure
and flow of a fluid.
Helicopter Rotor is the combination of several rotary wings (rotor
blades) and a control system that generates the aerodynamic lift force
that supports the weight of the
Helicopter, and the thrust that counteracts aerodynamic drag in
forward flight. Each main rotor is mounted on a vertical mast over the top
of the helicopter, as opposed to a helicopter tail rotor, which connects
through a combination of drive shaft(s) and gearboxes along the tail boom.
The blade pitch is typically controlled by a
swashplate connected to the helicopter flight controls. Helicopters
are one example of rotary-wing aircraft (rotorcraft). The name is derived
from the Greek words helix, helik-, meaning spiral; and pteron meaning wing.
Coandă Effect is the tendency of a fluid jet to stay attached to a
convex surface. It is named after Romanian inventor Henri Coanda, who
described it as "the tendency of a jet of fluid emerging from an orifice
to follow an adjacent flat or curved surface and to entrain fluid from the
surroundings so that a region of lower pressure develops." Coanda was the
first to recognize the practical application of the phenomenon in aircraft design.
Ground Effect is the increased lift and decreased aerodynamic drag
that an aircraft's wings generate when they are close to a fixed surface.
When landing, ground effect can give the pilot the feeling that the
aircraft is "floating". When taking off, ground effect may temporarily
reduce the stall speed. The pilot can then fly just above the runway while
the aircraft accelerates in ground effect until a safe climb speed is
reached. For rotorcraft, ground effect results in more power being
available during hovering which allows heavier weights to be lifted.
Helicopter pilots are provided with performance charts which show the
limitations for hovering their helicopter in ground effect (IGE) and out
of ground effect (OGE). The charts show the added lift benefit produced by
ground effect. For fan- and jet-powered VTOL aircraft, ground effect when
hovering can cause suckdown and fountain lift on the airframe and loss in
hovering thrust if the engine sucks in its own exhaust gas, which is known
as hot gas ingestion (HGI).
VTOL or a
vertical take-off and landing aircraft is one that can hover, take off, and land vertically.
Rotorcraft is a heavier-than-air flying machine that uses lift
generated by wings, called rotary wings or rotor blades, that revolve
around a mast. Several rotor blades mounted on a single mast are referred to as a rotor.
Aircraft
Principal Axes. An aircraft in flight is free to
rotate in
three
dimensions:
Yaw, nose
left or
right
about an axis running up and down;
Pitch,
nose
up or
down
about an axis running from wing to wing; and
Roll,
rotation about an axis running from nose to tail. The axes are
alternatively designated as vertical, transverse, and longitudinal
respectively. These axes move with the vehicle and rotate relative to the
Earth along with the craft. These definitions were analogously applied to
spacecraft when the first manned spacecraft were designed in the late
1950s. These rotations are produced by torques (or moments) about the
principal axes. On an aircraft, these are intentionally produced by means
of moving control surfaces, which vary the distribution of the net
aerodynamic force about the vehicle's center of gravity. Elevators (moving
flaps on the horizontal tail) produce pitch, a rudder on the vertical tail
produces yaw, and ailerons (flaps on the wings that move in opposing
directions) produce roll. On a spacecraft, the moments are usually
produced by a reaction control system consisting of small rocket thrusters
used to apply asymmetrical thrust on the vehicle.
Normal axis, or yaw axis — an axis drawn from top to bottom, and
perpendicular to the other two axes. Parallel to the fuselage station.
Transverse axis, lateral axis, or pitch axis — an axis running from
the pilot's left to right in piloted aircraft, and parallel to the wings
of a winged aircraft. Parallel to the buttock line.
Longitudinal axis, or roll axis — an axis drawn through the body of
the vehicle from tail to nose in the normal direction of flight, or the
direction the pilot faces. Parallel to the waterline. Normally, these axes
are represented by the letters X, Y and Z in order to compare them with
some reference frame, usually named x, y, z. Normally, this is made in
such a way that the X is used for the longitudinal axis, but there are
other possibilities to do it.
Vertical axis (yaw)
- The position of all three axes, with the right-hand rule for its
rotations.The yaw axis has its origin at the center of gravity and is
directed towards the bottom of the aircraft, perpendicular to the wings
and to the fuselage reference line. Motion about this axis is called yaw.
A positive yawing motion moves the nose of the aircraft to the right. The
rudder is the primary control of yaw. The term yaw was originally applied
in sailing, and referred to the motion of an unsteady ship rotating about
its vertical axis. Its etymology is uncertain.
Transverse axis (pitch). - The pitch axis (also called transverse
or lateral axis) has its origin at the center of gravity and is directed
to the right, parallel to a line drawn from wingtip to wingtip. Motion
about this axis is called pitch. A positive pitching motion raises the
nose of the aircraft and lowers the tail. The elevators are the primary
control of pitch.
Longitudinal axis (roll)
- The roll axis (or longitudinal axis) has its origin at the center of
gravity and is directed forward, parallel to the fuselage reference line.
Motion about this axis is called roll. An angular displacement about this
axis is called bank. A positive rolling motion lifts the left wing and
lowers the right wing. The pilot rolls by increasing the lift on one wing
and decreasing it on the other. This changes the bank angle. The ailerons
are the primary control of bank. The rudder also has a secondary effect on
bank.
6 Degrees of Motion.
Density of Air is the mass per unit volume of
Earth's
Atmosphere. Air density, like air pressure, decreases with increasing
altitude. It also changes with variation in temperature or humidity.
Altitude is defined
based on the
context in which it is used (aviation, geometry, geographical
survey, sport, and many more). As a general definition, altitude is a
distance measurement, usually in the vertical or "up" direction, between a
reference datum and a point or object.
Elevation mainly
used when referring to points on the Earth's surface, while altitude or
geopotential height is used for points above the surface, such as an
aircraft in flight or a
spacecraft in orbit, and depth is used for points
below the surface.
Wind
is the
flow of gases on a large scale.
Fans.
Wind Direction
is reported by the direction from which it originates. A northerly
Wind
blows from the north to the south.
Turbulence is fluid motion characterized by chaotic changes in
pressure and flow velocity. It is in contrast to a laminar flow, which
occurs when a fluid flows in parallel layers, with no disruption between
those layers.
Clear-Air Turbulence is the turbulent
movement of air masses in the
absence of any visual clues, such as
clouds, and is caused when bodies of air moving at widely different speeds
meet.
Wind
Shear is a
difference in wind
speed or direction over a relatively short distance in the atmosphere.
Atmospheric wind shear is normally described as either vertical or
horizontal wind shear. Vertical wind shear is a change in wind speed or
direction with change in altitude. Horizontal wind shear is a change in
wind speed with change in lateral position for a given altitude.
Thermal is a column of
rising air in the lower altitudes of Earth's
atmosphere, a form of
atmospheric
updraft. Thermals are created by the uneven heating of Earth's surface
from
solar radiation, and are an
example of
convection, specifically atmospheric convection. The
Sun warms
the ground, which in turn warms the air directly above it.
Convection is the
movement of groups of molecules within fluids such as gases and liquids,
including molten rock (rheid). Convection takes place through
advection, diffusion or both. Advection is the transport of a
substance by bulk motion.
Hot Air.
Gravity -
Vacuum
-
Cabin Pressure
Aviation Safety means the state of an aviation system or organization
in which risks associated with aviation activities, related to, or in
direct support of the operation of aircraft, are reduced and controlled to
an acceptable level. It encompasses the theory, practice, investigation,
and categorization of
flight failures, and the prevention of such failures through
regulation, education, and training. It can also be applied in the context
of campaigns that inform the public as to the safety of air travel.
19-year-old becomes the youngest woman to
fly solo around the world. Zara Rutherford set off from Belgium in
August to circle the globe in her Shark UL plane. Five months later, she
landed back home, having landed in 41 countries on five continents.
Going Solo.
De Havilland Canada DHC-2 Beaver is a single-engined high-wing
propeller-driven short takeoff and landing (STOL) aircraft developed and
manufactured by de Havilland Canada. It has been primarily operated as a
bush
plane and has been used for a wide variety of utility roles, such as
cargo and passenger hauling, aerial application (crop dusting and aerial
topdressing), and civil aviation duties. Shortly after the end of the
Second World War, de Havilland Canada made the decision to orient itself
towards civilian operators. Based upon feedback from pilots, the company
decided that the envisioned aircraft should have excellent STOL
performance, all-metal construction, and accommodate many features sought
by the operators of
bush planes. On 16 August 1947, the maiden flight of the aircraft,
which had received the designation DHC-2 Beaver, took place. In April
1948, the first production aircraft was delivered to the Ontario
Department of Lands and Forests. A Royal New Zealand Air Force (RNZAF)
Beaver played a supporting role in Sir Edmund Hillary's famous 1958
Commonwealth Trans-Antarctic Expedition to the South Pole. In addition to
its use in civilian operations, the Beaver has been widely adopted by
armed forces as a
utility aircraft. The United States Army purchased several hundred
aircraft; nine DHC-2s are still in service with the U.S. Air Force
Auxiliary (Civil Air Patrol) for search and rescue. By 1967, in excess of
1,600 Beavers had been constructed prior to the closure of the original
assembly line. Various aircraft have been remanufactured and upgraded.
Additionally, various proposals have been mooted to return the Beaver to
production. The Beaver's versatility and performance led to it being the
preferred aircraft of bush pilots servicing remote locations in the
Canadian north, and it is considered by aviation historians to be a
Canadian icon. In 1987, the Canadian Engineering Centennial Board named
the DHC-2 one of the top ten Canadian engineering achievements of the 20th
century. The Royal Canadian Mint honoured the aircraft on a special
edition Canadian quarter in November 1999, and on a 50-cent commemorative
gold coin in 2008. Large numbers continue to be operational into the 21st
century, while the tooling and type certificate for the Beaver have been
acquired by Viking Air who continue to produce replacement components and
refurbish examples of the type.
Drag - Friction
Drag is a
type of friction, or fluid resistance, another type
of friction or fluid friction) is a force acting opposite to the relative
motion of any object moving with respect to a surrounding fluid.
Aerodynamic Drag is the fluid drag force that acts on
any moving solid body in the direction of the fluid freestream flow.
Drag Coefficient
is a dimensionless quantity that is used to quantify the drag or
resistance of an object in a fluid environment, such as air or water. It
is used in the drag equation in which a lower drag coefficient indicates
the object will have less aerodynamic or hydrodynamic drag. The drag
coefficient is always associated with a particular surface area.
Drag
in physics
sometimes called air resistance, a type of friction, or fluid resistance,
another type of friction or fluid friction) is a force acting opposite to
the relative motion of any object moving with respect to a surrounding
fluid. This can exist between two fluid layers (or surfaces) or a fluid
and a solid surface. Unlike other resistive forces, such as dry friction,
which are nearly independent of velocity, drag forces depend on velocity.
Drag force is proportional to the velocity for a laminar flow and the
squared velocity for a turbulent flow. Even though the ultimate cause of a
drag is viscous friction, the turbulent drag is independent of viscosity.
Friction is the
force resisting the relative
motion of solid surfaces,
fluid layers, and material elements sliding against each other. There
are several types of friction:
Dry friction
is a force that opposes the relative lateral motion of two solid surfaces
in contact. Dry friction is subdivided into static friction ("stiction")
between non-moving surfaces, and kinetic friction between moving surfaces.
With the exception of atomic or molecular friction, dry friction generally
arises from the interaction of surface features, known as asperities.
Fluid friction describes the friction
between layers of a
viscous
fluid that are moving relative to each other.
Lubricated friction is a case of fluid
friction where a
lubricant fluid separates two solid surfaces.
Skin friction is a component of drag, the
force resisting the motion of a fluid across the surface of a body.
Internal friction is the force resisting
motion between the elements making up a solid material while it undergoes
deformation. When surfaces in contact move relative to each other, the
friction between the two surfaces converts
kinetic energy into
thermal energy (that is, it
converts work to
heat). This property can have dramatic consequences.
Laser-cooled ions contribute to better understanding of friction.
Skin
Friction Drag is a component of profile drag, which is resistant force
exerted on an object moving in a fluid. Skin friction drag is caused by
the viscosity of fluids and is developed from laminar drag to turbulent
drag as a fluid moves on the surface of an object. Skin friction drag is
generally expressed in terms of the Reynolds number, which is the ratio
between inertial force and viscous force.
Frictional Force refers to the force generated by two surfaces that
contacts and slide against each other. These forces are mainly affected by
the surface texture and quantity of force requiring them together. The
angle and position of the object affect the volume of frictional force.
Laminar-Turbulent Transition is the process of a laminar flow becoming
Turbulent, which is a flow regime in fluid dynamics characterized by
chaotic changes in pressure and flow velocity. It is in contrast to a
laminar flow regime, which occurs when a fluid flows in parallel layers,
with no disruption between those layers.
Fluid Dynamics
describes the flow of fluids (liquids and gases).
Atmosphere -
Pressure -
Superconductivity
Windshield
is the front window generally made of laminated safety glass, a type of
treated glass, which consists of two (typically) curved sheets of glass
with a plastic layer laminated between them for safety, and are bonded
into the window frame. Motorbike windshields are often made of high-impact
acrylic plastic.
CAVU is an
aeronautical term that stands for "Ceiling and
Visibility Unlimited".
Why are plane
windows round? (youtube)
Stress
Concentration is a location in an object where stress is concentrated.
An object is strongest when force is evenly distributed over its area, so
a reduction in area, e.g., caused by a crack, results in a localized
increase in stress. A material can fail, via a propagating crack, when a
concentrated stress exceeds the material's theoretical cohesive strength.
The real fracture strength of a material is always lower than the
theoretical value because most materials contain small cracks or
contaminants (especially foreign particles) that concentrate stress.
Fatigue cracks always start at stress raisers, so removing such defects
increases the fatigue strength.
Center of Mass of a distribution of
mass in space is the unique
point where the weighted
relative position of the distributed mass sums to
zero, or the point where if a force is applied it moves in the
direction
of the force without rotating. The distribution of mass is
balanced around the
center of mass and the
average of the weighted position
coordinates of the distributed mass defines its coordinates. Calculations
in mechanics are often simplified when formulated with respect to the
center of mass. It is a hypothetical point where entire mass of an object
may be assumed to be concentrated to visualise its motion. In other words,
the center of mass is the particle equivalent of a given object for
application of
Newton's laws of motion.
In the case of a single rigid body, the center of mass is fixed in
relation to the body, and if the body has uniform density, it will be
located at the centroid. The center of mass may be located outside the
physical body, as is sometimes the case for hollow or open-shaped objects,
such as a horseshoe. In the case of a distribution of separate bodies,
such as the planets of the Solar System, the center of mass may not
correspond to the position of any individual member of the system. The
center of mass is a useful reference point for calculations in mechanics
that involve masses distributed in space, such as the linear and angular
momentum of planetary bodies and rigid body dynamics. In orbital
mechanics, the equations of motion of planets are formulated as point
masses located at the centers of mass. The center of mass frame is an
inertial frame in which the center of mass of a system is at rest with
respect to the origin of the coordinate system.
Pivot axes.
Cabin
Pressurization is a process in which conditioned air is pumped into
the cabin of an aircraft or spacecraft, in order to create a safe and
comfortable environment for passengers and crew flying at high altitudes.
For aircraft, this air is usually bled off from the gas turbine engines at
the compressor stage, and for spacecraft, it is carried in high-pressure,
often cryogenic tanks. The air is cooled, humidified, and mixed with
recirculated air if necessary, before it is distributed to the cabin by
one or more environmental control systems. The cabin pressure is regulated
by the outflow valve.
Weather
Wiz Kids -
Weather effects
on Mood
STRAPPED INTO A
FALLING HELICOPTER - Smarter Every Day 154 (youtube)
Autorotation is a state of flight in which the main rotor system
of a helicopter or similar aircraft turns by the action of air moving up
through the rotor, as with an autogyro, rather than engine power driving
the rotor. (adjust collective pinwheel).
Engineers Fly first-ever Plane with No Moving Parts. Instead of
propellers or turbines, the light aircraft is powered by an 'ionic wind'
-- a silent but mighty flow of ions that is produced aboard the plane, and
that generates enough thrust to propel the plane over a sustained, steady
flight.
Space Flight.
Wingless Electromagnetic Air Vehicle uses a multitude of small
electrodes covering the whole wetted area of the aircraft, in a
multi-barrier plasma actuator (MBPA) arrangement, an enhancement over
dual-electrode dielectric barrier discharge (DBD) systems using multiple
layers of dielectric materials and powered electrodes. These electrodes
are very close to one another so surrounding air can be ionized using RF
AC high voltage of a few tens of kilovolts even at the standard pressure
of one atmosphere. The resultant plasma contains ions that are accelerated
by the Coulomb force using
electrohydrodynamics
(EHD) at low altitude and small velocity. The surface of the vehicle acts
as an electrostatic fluid accelerator pumping surrounding air as ion wind,
radially then downward, so the lower pressure zone on the upper surface
and the higher pressure zone underneath the aircraft produces lift and
thrust for propulsion and stability. At a higher altitude and to reach
greater speeds, a
magnetic
field is also applied to enhance collisions between electrons and
heavy species in the plasma and use the more powerful Lorentz body force
to accelerate all charge carriers in the same direction along a radial
high speed jet.
Ion Wind
is the airflow induced by
electrostatic
forces linked to corona discharge arising at the tips of some sharp
conductors (such as points or blades) subjected to high voltage relative
to ground. Ion wind is an electrohydrodynamic phenomenon. Ion wind
generators can also be considered electrohydrodynamic thrusters. The term
“ionic wind” is considered a misnomer due to misconceptions that only
positive and negative ions were primarily involved in the phenomenon.
Ionocraft is a device that uses an electrical electrohydrodynamic (EHD)
phenomenon to produce thrust in the air without requiring any combustion
or moving parts.
Orbital Mechanics.
Bird Flight Mechanics
Bird Flight is the
primary mode of
locomotion used by most bird species in which birds take off and fly.
Flight assists birds with feeding, breeding, avoiding predators, and
migrating. Bird flight is one of the most complex forms of locomotion in
the animal kingdom. Each facet of this type of
motion,
including hovering, taking off, and landing, involves many complex
movements. As different bird species adapted over millions of years
through evolution for specific environments, prey, predators, and other
needs, they developed specializations in their wings, and acquired
different forms of flight. Various theories exist about how bird flight
evolved, including flight from falling or gliding (the trees down
hypothesis), from running or leaping (the ground up hypothesis), from
wing-assisted incline running or from proavis (pouncing) behavior.
Most
Birds can Fly, which distinguishes them from almost all other
vertebrate classes. Flight is the primary means of locomotion for most
bird species and is used for searching for food and for escaping from
predators. Birds have various adaptations for flight, including a
lightweight skeleton, two large flight muscles, the pectoralis (which
accounts for 15% of the total mass of the bird) and the supracoracoideus,
as well as a modified forelimb (
wing) that serves as an aerofoil. Wing
shape and size generally determine a bird's flight style and performance;
many birds combine powered, flapping flight with less energy-intensive
soaring flight. About 60 extant bird species are flightless, as were many
extinct birds. Flightlessness often arises in birds on isolated islands,
probably due to limited resources and the absence of land predators.
Although flightless, penguins use similar musculature and movements to
"fly" through the water, as do some flight-capable birds such as auks,
shearwaters and dippers.
Learning on the fly. Computational model demonstrates similarity in
how humans and insects learn about their surroundings. Informatics
experts have developed a new computational model that demonstrates a long
sought after link between insect and mammalian learning. Even the humble
fruit fly craves a dose of the happy hormone, according to a new study
from the University of Sussex which shows how they may use dopamine to
learn in a similar manner to humans.
Dragonflies use vision, subtle wing control to straighten up and fly right.
Researchers have untangled the intricate physics and neural controls that
enable dragonflies to right themselves while they're falling. A visual cue
triggers a series of reflexes that sends neural signals to the dragonfly's
four wings, which are driven by a set of direct muscles that modulate the
left-wing and right-wing pitch asymmetry accordingly. With three or four
wing strokes, a tumbling dragonfly can roll 180 degrees and resume flying
right-side up. The entire process takes about 200 milliseconds.
Advanced
Robotic Bat Can Fly Like the Real Thing (youtube)
Engineers Build Robot Drone That Mimics Bat Flight.
Songs about FlyingLearning to
Fly - Tom Petty and the Heartbreakers.
Learning to Fly - Pink Floyd
Free Bird - Lynyrd Skynyrd
Fly Away - Lenny Kravitz
Jet Airliner -
Steve Miller Band
Leaving on a Jet Plane - Peter, Paul & Mary
Learn To Fly - Foo
Fighters (youtube) - Run and tell all of the angels, This could take
all night, Think I need a devil to help me get things right, Hook me up a
new revolution, Cause this one is a lie, We sat around laughin' and
watched the last one die, Now,
I'm lookin' to the
sky to save me, Lookin' for a sign of life, Lookin' for somethin'
to help me burn out bright, And I'm lookin' for a complication, Lookin'
cause I'm tired of lyin', Make my way back home
when I learn to fly high, I think I'm dyin' nursing patience, It
can wait one night, I'd give it all away if you give me one last try,
We'll live happily ever trapped if you just save my life, Run and tell the
angels that everything's alright, Now I'm lookin' to the sky to save me,
Lookin' for a sign of life, Lookin' for somethin' to help me burn out
bright, I'm lookin' for a complication, Lookin' cause I'm tired of tryin',
Make my way back home when I learn to fly high,
Make my way back home when I learn to, Fly along with me, I can't quite
make it alone, Try to make this life my own,
Fly
along with me, I can't quite make it alone, Try to make this life
my own, I'm lookin' to the sky to save me, Lookin' for a sign of life,
Lookin' for somethin' to help me burn out bright, And I'm lookin' for a
complication, Lookin' cause I'm tired of tryin', Make my way back home
when I learn to, I'm lookin' to the sky to save me, Lookin' for a sign of
life, Lookin' for somethin' to help me burn out bright, And I'm lookin'
for a complication, Lookin' cause I'm tired of tryin',Make my way back
home when I learn to fly high, Make my way back home when I learn to fly,
Make my way back home when I learn to.