Physics Flash Cards

Front 1

Controlled Experiment

Back 1

A form of scientific investigation in which one variable, termed the independent or control variable, is manipulated to reveal the effect on another variable, termed the dependent or responding variable, while all other variables in the system are held fixed.

Front 2

Model

Back 2

a hypothetical description of a complex entity or process

Front 3

Precision

Back 3

being reproducible in amount or performance

Front 4

Significant Figure

Back 4

The digits in a measurement that are reliable

Front 5

System

Back 5

a group of independent but interrelated elements comprising a unified whole

Front 6

Acceleration

Back 6

The rate at which an objects velocity changes over time.

Front 7

Average acceleration

Back 7

acceleration over a finite time.

Front 8

Displacement

Back 8

removal from normal position or place

Front 9

Average velocity

Back 9

Velolcity measured over a finite time interval

Front 10

Constant acceleration

Back 10

acceleration changing by a constant amount each second

Front 11

Free Fall

Back 11

falling with acceleration due to gravity acting on a body alone

Front 12

Free fall acceleration

Back 12

9.8 meters per second squared

Front 13

Velocity

Back 13

speed/ distance traveled in a unit of time

Front 14

Components of a vector

Back 14

magnatude and direction

Front 15

Frame of reference

Back 15

a place where position or movement may be specified or referenced from

Front 16

Accuracy

Back 16

The quality of being near to a true a value.

Front 17

Projectile Motion

Back 17

The motion of a moving object with a constant force acting on it

Front 18

Resultant

Back 18

The resultant of a system of forces is a single force or moment whose magnitude, direction, and location make it statically equivalent to the system of forces.

Front 19

Scalar

Back 19

A quantity, such as mass, length, or speed, that is completely specified by its magnitude and has no direction.

Front 20

Vector

Back 20

A qantity, such as velocity, completely specified by a magnitude and a direction.

Front 21

Action-Reaction pair

Back 21

for every action there is an equal and opposite reaction

Front 22

Coefficient of Friction

Back 22

a dimensionless scalar value which describes the ratio of the force of friction between two bodies and the force pressing them together.

Front 23

Contact force

Back 23

A force between objects in contact with each other.

Front 24

Equilibrium

Back 24

a stable situation in which forces cancel one another

Front 25

Field Force

Back 25

a vector field indicating the forces exerted by one object on another

Front 26

Force

Back 26

The rate of change of momentum with time.

Front 27

Force Diagram

Back 27

Graphical solution of axial forces

Front 28

Inertia

Back 28

The tendency of an object to resist change.

Front 29

Kinetic Friction

Back 29

The force exerted on one surface by a second surface when the two rub on each other.

Front 30

Net External Force

Back 30

outside force resulting in a change in velocity

Front 31

Normal force

Back 31

perpendicular force that a surface exerts on an object with which it is in contact.

Front 32

Static Friction

Back 32

Friction at rest; a force is required to initiate relative movement between two bodies - static friction is the force that resists such relative movement. Sometimes referred to as stiction.

Front 33

Weight

Back 33

the vertical force exerted by a mass as a result of gravity

Front 34

Elastic potential energy

Back 34

The energy in a solid object when it is stretched or compressed. A stretched rubber band has elastic potential energy.

Front 35

Gravitational potential energy

Back 35

a type of potential energy. Gravitational potential energy is associated in the interaction of an object with the earth. It is defined to be equal to the mass of the object times the gravitational acceleration times the distance of the object from the ground.

Front 36

Kinetic Energy

Back 36

energy resulting from motion

Front 37

Mechanical energy

Back 37

the sum of the kinetic andand gravitational potential energy of a system

Front 38

potential energy

Back 38

stored energy

Front 39

power

Back 39

the work done over time

Front 40

Spring constant

Back 40

measure of stiffness or strength of a spring

Front 41

Work

Back 41

the product of the force exerted on an object and the displacement

Front 42

Parallel

Back 42

Two lines with the same slope. Lines never intersect on a two dimensional plane

Front 43

Schematic diagram

Back 43

Illustration of an electrical or electronic circuit with the components represented by their symbols.

Front 44

Series

Back 44

the sum of a sequence of terms.

Front 45

Work-Kinetic Energy Theorem

Back 45

The kinetic energy of a particle changes by the amount of work done on it.

Front 46

Elastic Collision

Back 46

A collision in which no kinetic energy is lost.

Front 47

Impulse

Back 47

The act of applying force suddenly

Front 48

Momentum

Back 48

The product of the mass times the velocity of an object.

Front 49

Perfectly inelastic collision

Back 49

A collision in which the colliding objects become distorted and/or generate heat during the collision.

Front 50

Angular acceleration

Back 50

Angular acceleration is the rate of change of angular velocity over time.

Front 51

Centripetal acceleration

Back 51

The acceleration on a particle moving in a curved path, directed toward the instantaneous center of curvature of the path, with magnitude V 2 /R, where V is the speed of the particle and R the radius of curvature of the path. This acceleration is equal and opposite to the centrifugal force per unit mass.

Front 52

Gravitational force

Back 52

the weakest of the four fundamental forces of nature. Described by Newton's universal theory of gravity, and subsequently by Einstein's general relativity.

Front 53

Radian

Back 53

The measure of an angle in terms of pi. the measure of one radian is approximately 57 degrees

Front 54

Rotational motion

Back 54

Rotational motion is similar to circular motion, except that it is unique by which the object involved rotates around itself and not a point of centrifugal force.

Front 55

tangential acceleration

Back 55

The component of the acceleration directed along the velocity vector (streamline), with magnitude equal to the rate of change of speed of the parcel dV/dt, where V is the speed. In horizontal, frictionless atmospheric flow, the tangential acceleration is balanced by the tangential pressure force, where is the specific volume, p the pressure, and s a coordinate along the streamline. Thus, flow without tangential acceleration is along the isobars, and the wind is the gradient wind.

Front 56

Tangential speed

Back 56

Component of velocity tangent to the trajectory of a projectile.

Front 57

ANgular momentum

Back 57

The energy of motion of a spinning body or mass of air or water. Its value depends on the mass of the body, its radius of spin, and its rate of spin.

Front 58

Center of Mass

Back 58

The point about which the sum of all the linear moments of mass of the particles in a body is zero

Front 59

Lever Arm

Back 59

A lever arm, also called a moment arm or bell crank, is a rigid bar or beam free to turn around a fixed point (fulcrum). Also, when applying torque, lever arm refers to the distance between the point where the force acts and the point of rotation.

Front 60

Moment of inertia

Back 60

Moment of inertia has two distinct but related meanings: 1) it is a property of a an object relating to the magnitude of the moment required to rotate the object and overcome its inertia. 2) A property of a two dimensional cross section shape with respect to an axis, usually an axis through the centroid of the shape.

Front 61

Rotationbal kinetic energy

Back 61

* Rotating objects contain kinetic energy. An object's rotational energy or angular kinetic energy is part of its total kinetic energy. Looking at rotational energy separately in an object's centre of mass frame, one gets the following dependence on the object's moment of inertia: In SI units, rotational energy is measured in joules.

Front 62

Torque

Back 62

The force which tends to cause rotation.

Front 63

Bernoulli's Principle

Back 63

The law, discovered by Daniel Bernoulli, which states that when air speeds up its pressure is reduced, and when the air slows down its pressure is increased.

Front 64

Buoyant Force

Back 64

The upward pressure exerted on an object by a fluid in which the object rests.

Front 65

Fluid

Back 65

A subset of the phases of matter, fluids include liquids, gases, plasmas and, to some extent, plastic solids.

Front 66

Ideal Fluid

Back 66

In fluid mechanics, an incompressible fluid is a fluid whose density (often represented by the Greek letter ρ) is constant: it is the same throughout the field and it does not change through time. It is an idealization used to simplify analysis. In reality, all fluids are compressible to some extent.

Front 67

Mass Density

Back 67

Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. The higher an object's density, the higher its mass per volume. The average density of an object equals its total mass divided by its total volume. A denser object (such as iron) will have less volume than an equal mass of some less dense substance (such as water).

Front 68

Pressure

Back 68

Pressure is the application of force to a surface, and the concentration of that force in a given area. A finger can be pressed against a wall without making any lasting impression; however, the same finger pushing a thumbtack can easily damage the wall, even though the force applied is the same, because the point concentrates that force into a smaller area.

Front 69

TemperatureA crest is the section of a wave that rises above an undisturbed position.
en.wikipedia.org/wiki/Crest_(Physics)

Back 69

Temperature is the physical property of a system which underlies the common notions of "hot" and "cold"; the material with the higher temperature is said to be hotter. Temperature is a measure of the average kinetic energy of the particles in a sample of matter.

Front 70

Amplitude

Back 70

(physics) the maximum displacement of a periodic wave

Front 71

Antinodes

Back 71

The positions on a standing wave where the largest amplitudes occur

Front 72

Constructive Force

Back 72

Interference that occurs when waves occupying the same space combine to form a single stronger wave. The strength of the composite wave depends on the how close in phase the two component waves are. For example if you transmitted two waves of the same phase, each with an amplitude of 10, they would combine into a composite wave of amplitude 20, but two waves slightly out of phase would combine into a composite wave of amplitude less than 20.

Front 73

Crest

Back 73

A crest is the section of a wave that rises above an undisturbed position.

Front 74

Destructive interference

Back 74

Combination of waves where crest parts of one wave overlap trough parts of another; resulting in a wave of decreased ampli­tude

Front 75

Frequency

Back 75

Frequency is the measurement of the number of times that a repeated event occurs per unit time. To calculate the frequency, one fixes a time interval, counts the number of occurrences of the event within that interval, and then divides this count by the length of the time interval.

Front 76

Longitudinal wave

Back 76

Longitudinal waves, also referred to as compressional waves or pressure waves, are waves that have vibrations along or parallel to their direction of travel and can be a wave in which the motion of the medium is in the same direction to the motion of the wave. Examples of longitudinal waves include sound waves (alternation in pressure, particle displacement, or particle velocity propagated in an elastic material) and seismic P-waves (created by earthquakes and explosions).

Front 77

Mechanical wave

Back 77

A wave which needs a medium in order to propagate itself. Sound waves, waves in a Slinky, and water waves are all examples of this. Sound waves need air molecules in order to exist; the Slinky waves need the Slinky, and the waves in the ocean need the water.

Front 78

Medium

Back 78

Free space is the most simple and elementary electromagnetic medium. A medium is the stuff that waves propagate through. The properties, permittivity and permeability, define how electromagnetic waves travel through a medium. Also, the medium has an ''intrinsic impedance: where is the permeability of the medium and is the permittivity of the medium.

Front 79

Node

Back 79

(physics) the point of minimum displacement in a periodic system

Front 80

Period

Back 80

the time required for one cycle in a periodic waveform. Period is the inverse of frequency.

Front 81

Periodic Wave

Back 81

A wave whose displacement has a periodic variation with time or distance, or both.

Front 82

Pulse Wave

Back 82

alternates regularly and instantaneously between two levels, which may or may not include zero.

Front 83

Simple Harmonic motion

Back 83

Motion such that the displacement is a sinusoidal function of time

Front 84

Standing wave

Back 84

Periodic wave having a fixed distribution in space which is the result of interference of progressive waves of the same frequency and kind. Such waves are characterized by the existence of nodes or partial nodes and antinodes that are fixed in space.

Front 85

Transverse Wave

Back 85

A wave in which the vibration is moving in a direction perpendicular as that in which the wave is traveling

Front 86

Trough

Back 86

the lowest point of a wave

Front 87

Wavelength

Back 87

The distance between successive points of equal amplitude and phase on a wave (for example, crest to crest or trough to trough).

Front 88

Beat

Back 88

pulsate: move with or as if with a regular alternating motion

Front 89

Compression

Back 89

Compaction: an increase in the density of something

Front 90

Decibel LEvel

Back 90

A unit used to convey the intensity of sound.

Front 91

Doppler Effect

Back 91

A shift in the frequency of an electromagnetic or sound wave due to the relative movement of the source or the observer.

Front 92

Fundamental frequency

Back 92

the predominant frequency in a complex waveform. Typically provides the sound with its strongest pitch reference.

Front 93

Harmonic Series

Back 93

The infinite sum of the inverse of all the natural numbers, N. from N = 1 to infinity

Front 94

INtensity

Back 94

In physics, intensity is a measure of the time-averaged energy flux. To find the intensity, take the energy density (that is, the energy per unit volume) and multiply it by the velocity at which the energy is moving. The resulting vector has the units of power divided by area (i.e. watt/m²). It is possible to define the intensity of the water coming from a garden sprinkler, but intensity is used most frequently with waves (i.e. sound or light).

Front 95

Pitch

Back 95

Perceptual correlate of the frequency of a sound wave. In general, the higher the perceived pitch, the higher the frequency.

Front 96

Rarefaction

Back 96

The part of a longitudinal wave which is stretched out, where as a compression is the part which is pushed together. (longitudinal wave)

Front 97

Resonance

Back 97

the state of a system in which an abnormally large vibration is produced in response to an external stimulus, occurring when the frequency of the stimulus is the same, or nearly the same, as the natural vibration frequency of the system.

Front 98

Timbre

Back 98

This is a subjective quality that enables listeners to tell the difference between two sound of identical pitch at the same volume. Fundamentally it is the difference in frequency content of the sounds.

Front 99

ANgle on incidence

Back 99

This is a subjective quality that enables listeners to tell the difference between two sound of identical pitch at the same volume. Fundamentally it is the difference in frequency content of the sounds.

Front 100

Angle of reflection

Back 100

The angular measure between a reflected light ray and the normal to the reflecting surface. For any surface, the angle of incidence equals the angle of reflection.

Front 101

Concave Spherical Mirror

Back 101

used to collect and concentrate light at a point

Front 102

Convex Spherical Mirror

Back 102

In a convex spherical mirror the vertex of the mirror is nearer to the object than the edges—the mirror bulges toward the object. The image formed by it is always smaller than the object and always erect. It is never real because the reflected rays diverge outward from the face of the mirror and are not brought to a focus, and the image, therefore, is determined by their prolongation behind the mirror as in the case of the plane mirror.

Front 103

Electromagnetic Wave

Back 103

an electric field spreading in wavelike-fashion through space at a speed of about 300 000 km.sec, with its direction and intensity at any point in space oscillating rapidly back and forth. James Clerk's Maxwell's theory in 1864 suggested that light was such a wave, and today we know that such waves include all forms of light--also infra-red and ultra-violet, as well as radio waves, microwaves, x-rays and gamma rays.

Front 104

Linear polarization

Back 104

In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. See polarization for more information.

Front 105

Real Image

Back 105

The point(s) to which light rays converge as they emerge from a lens or mirror

Front 106

Reflection

Back 106

#

# Reflection is the abrupt change in direction of a wave front at an interface between two dissimilar media so that the wave front returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves.

Front 107

Virtual Image

Back 107

The point(s) from which light rays converge as they emerge from a lens or mirror. The rays do not actually pass through each image point, but diverge from it. See: real image.

Front 108

Chromatic aberration

Back 108

Color shifts and color artifacts in an image caused by faults in a lens, or by the camera’s inability to register all three channels of color information. Single-chip video cameras are especially prone to chromatic abberation.

Front 109

Critical Angle

Back 109

The angle at the interface between core and cladding where a guided ray in the core undergoes total internal reflection.

Front 110

Dispersion

Back 110

In optics, dispersion is a phenomenon that causes the separation of a wave into spectral components with different frequencies, due to a dependence of the wave's speed on its frequency. It is most often described in light waves, though it may happen to any kind of wave that interacts with a medium or can be confined to a waveguide, such as sound waves.

Front 111

Index of refraction

Back 111

the ratio of the speed of light in a vacuum to the speed of light in a substance

Front 112

Lenses

Back 112

A variety of structures that apparently affect the directionality of light are called "lenses." Some of these appear to act like typical optical lenses but the mode of action of others (like those in the illustration to the right) are uncertain.

Front 113

Refraction

Back 113

The bending of light as it passes from one medium to another

Front 114

Total internal reflection

Back 114

When a light beam strikes the interface of two media of different diffractive indices, at an angle beyond the critical angle, all of the light energy is reflected back into the incident medium. In this situation, an 'evanescent field' develops at the interface with an energy that decreases exponentially into the medium with the lower refractive index. This allows selective excitation of fluorophores located within ~100 nm of the interface.

Front 115

Conductor

Back 115

a substance that readily conducts e.g. electricity and heat

Front 116

Electrical Field

Back 116

In physics, an electric field or E-field is an effect produced by an electric charge that exerts a force on charged objects in its vicinity. The units of the electric field are newtons per coulomb or volts per meter (both are equivalent). Electric fields are composed of photons and contain electrical energy with energy density proportional to the square of the field intensity. .

Front 117

Induction

Back 117

an electrical phenomenon whereby an electromotive force (EMF) is generated in a closed circuit by a change in the flow of current

Front 118

Insulator

Back 118

Something that does not allow electricity to flow through it easily. Glass and special rubber are good insulators. Insulators do not allow electricity to flow through them easily because the electrons in their atoms do not move easily from atom to atom.

Front 119

Capacitance

Back 119

The property of a circuit element that allows it to store an electrical charge

Front 120

Electrical POtential

Back 120

Electric potential is the potential energy per unit charge associated with a static (time-invariant) electric field, also called the electrostatic potential, typically measured in volts. Metaphorically, electric potential may be conceived of as "electric pressure" that can push electric charges to different locations.

Front 121

Electrical potential energy

Back 121

Energy stored by separating positive and negative electrical charges against electrical forces. A charged battery has electrical potential energy. See Electrical (Electromagnetic) energy.

Front 122

POtential difference

Back 122

The voltage difference between two points. Electricity flows from a high to low level of potential

Front 123

COherence

Back 123

Property of superposed waves generated by a single source. They demonstrate coherence when a defined relationship exists between their phases. The advantage of measurement using coherent radiation is that not only the intensity, but also the phase of the radiation can be measured after scattering by the sample under investigation. The smaller the radiation source, the more coherent the radiation.

Front 124

Diffraction

Back 124

The bending of light around objects, such as cloud and fog droplets, producing fringes of light and dark or colored bands.

Front 125

Laser

Back 125

) A device that concentrates light into an intense, narrow beam used to cut or destroy tissue. It is used in microsurgery, photodynamic therapy, and for a variety of diagnostic purposes.