Physics Glossary CliffsNotes Flashcards
CliffsQuickReview
Absorption Spectrum
The specific wavelengths of light absorbed by a gas
Acceleration
(Vector; m/s^2) The rate of change in velocity
Adiabatic
Without the exchange of heat with the external universe
Alternating Current
(Scalar; A) A type of electrical current that changes direction regularly in time
Alternating Voltage
An electrostatic potential that changes regularly in time
Ammeter
A device used to measure electrical current
Ampere
(A) The SI unit of measurement of current; equivalent to Coulombs/s
Amplitude
(Scalar; m) The maximal displacement of an object in simple harmonic motion; the peak-to-peak height of a wave
Angular Acceleration
(Scalar; radians/s^2) The rate of change of angular velocity in time
Angular Displacement
(Scalar; radians) The angle between the initial and final radii after a given time of an object moving in a circle
Angular Momentum
(Vector; J-s) The cross product of the distance an object is from point and its momentum with respect to this point
Angular Velocity
(Scalar; radians/s) The rate of change of angular displacement in time
Antinodes
Points on a standing wave that have maximum displacement, due to the constructive interference of the component waves
Atomic Mass
The total number of nucleons in a nucleus
Atomic Mass Unit
(amu) The unit of mass appropriate to the nucleus of an atom, equivalent to 1/12 of the mass of a carbon nucleus
Atomic Number
The number of protons in a nucleus
Avogadro’s Number
(6.02214×10^23) The number of objects or particles in a mole of substance
Beats
The effect produced by interference of waves of slightly different frequency, producing a pattern of alternating intensity
Binding Energy
The energy difference between the mass energy of a nucleus and its separate constituent particles. Binding energy is released when nuclei come together during fusion
Blackbody
An object that absorbs all radiation falling on it and radiates it perfectly
Bohr Radius
(5.29×10^-11 m) The average radius of an electron orbiting a single proton
Boltzmann’s Constant
(1.38×10^-23 J/K) A fundamental constant, usually encountered in thermodynamics
British Thermal Unit
(252 calories of 1.054 kJ) A unit of energy frequently used in engineering
Bulk Modulus
(Scalar; N/m^2) The ration of pressure to the resulting compressional strain
Buoyant Force
The upward force on an object placed in a fluid
Calorie
(cal) A unit of energy, defined as the energy needed to raise one gram of water by one degree Celsius, and equivalent to 4.184 J
Calirometer
A device used to measure the specific heat capacity of a substance
Capacitance
(Scalar; F) A measure of how much charge a capacitor can store
Capacitor
An electrical device for storing separated charge and therefore storing electrostatic potential energy
Carnot Cycle
An ideal series of states through which a heat engine may move, which maximizes the amount of heat converted into work. The Carnot cycle consists of two isothermal processes and two adiabatic processes
Centripetal Acceleration
(Vector; m/s^2) the acceleration of an object in uniform circular motion which is pointed toward the center of the circle
Centripetal Force
(Vector; N) The force that holds an object in circular motion, pointed toward the center of the circle
Charge
(Scalar; C) An intrinsic property of matter that causes it to produce an electric field and, when it is moving, a magnetic field, and to feel a force due to these fields as well
Circuit
A closed loop arrangement of elements such as capacitors, resistors, inductors, and batteries, through which electrical current flows
Compressional Strain
(Scalar) The fractional volume change of an object due to uniform pressure
Compton Scattering
The deflection of electrons by photons
Concave Mirror
A mirror with an inwardly curved surface, such as the inner surface of a sphere
Conduction
The transfer of heat through a stationary substance; also the movement of ions or electrons through a material
Conductor
A material through which electrical charges can easily flow
Conservation of Energy
A fundamental law of physics which states that the energy of a system does not change unless an external force acts upon the system
Constructive Interference
The phenomenon in which waves present simultaneously at the same position add together to form a bigger wave
Convection
The transport of heat due to the motion of heated substance, such as a gas
Converging Lens
A lens that causes parallel light rays to converge
Convex Mirror
A mirror with an outwardly curved surface, such as the outer surface of a sphere
Coloumb
(C) The SI unit of measurement of charge
Critical Angle
The angle of incidence for a light ray, below which total internal reflection occurs
Current
(Scalar; A) The amount of electric charge passing a point per unit time
Daughter Nucleus
The nucleus remaining after a radioactive decay
Degrees
(°) The gradations of a temperature scale; also a unit of measurement of an angle
Density
(Scalar; kg/m3) Mass per unit volume
Destructive Interference
The phenomenon in which waves present simultaneously at the same position add together to form a smaller wave, or momentarily cancel entirely
Dichroic
Having the property of naturally emitting light with only a single polarization
Dielectric Constant
(Scalar) An intrinsic property of a substance that indicates the amount of charge induced in the substance when it is placed in an electric field
Diffraction
The process of a wave spreading as it passes around an object or passes through a narrow opening
Direct Current
(Scalar; A) A type of electrical current that flows in only one direction. Direct current flows between the terminals of a simple battery when they are connected to a circuit
Dispersion
The effect of separating waves, especially light, into constituent wavelengths by passing through a medium with an index of refraction that varies with wavelengths
Displacement
(Vector; m) Change in position of an object
Diverging Lens
A lens that causes parallel light rays to diverge
Doppler Effect
The change in frequency of a wave produced by a moving source. Approaching sources have a higher frequency, and retreating sources have a lower frequency
Elastic Collision
A collision between two objects in which the kinetic energy of both is conserved
Elastic Modulus
(Scalar; N/m2) The ratio of stress to strain
Elasticity
The property of an object to restore its shape after deformation
Electric Field
(Vector; V/m) The force felt by a positive unit test charge in a region of space, due to the influence of other charges. Electric fields are produced by stationary and moving charges
Electric Flux
(Scalar; V-m) The total sum of electric field vectors passing perpendicularly through a surface. According to Gauss’s law, the electric flux through a closed gaussian surface is proportional to the total net charge contained within the surface
Electromotive Force
(emf; scalar; V) The electrostatic potential difference between the terminals of a circuit or battery when no current is flowing
Electron
The negatively charged fundamental particles present in ordinary matter, surrounding the nucleus
Electroscope
A simple device for indicating the presence of net electrical charge
Electrostatic Pressure
(Scalar; V) The amount of energy per unit positive charge required to move a charge between two points within an electric field
emf
(Scalar; V) The electrostatic potential difference between the terminals of a circuit or battery when no current is flowing. Also called electromotive force
Emmisivity
(Scalar) An intrinsic property of a material indicating how well it radiates heat
Energy
(Scalar; J) The ability to do work
Energy Level Diagram
A diagram illustrating the discrete energies that an electron orbiting a nucleus may possess
Entropy
(Scalar; J/K) A fundamental thermodynamic quantity which measures how much heat energy is unavailable for conversion to work
Equipotential Surface
An array of positions within an electric field that all have the same electrostatic potential value. A charge may move along an equipotential surface without requiring or releasing energy
Equivalence Potential
The principle of general relativity which states that experiments conducted in an inertial frame in a gravitational field and experiments conducted in an accelerating reference frame will give the same results
Luminiferous Aether
The medium on which light waves were once presumed to propagate
Note: Luminiferous Ether is fictional
Farad
(F) The SI unit of measurement of capacitance; equivalent to A-s/V
Field Lines
A pictorial representation of an electric field or magnetic field or any other vector field
Focal Length
(Scalar; m) The distance from the focal point of a lens or mirror to the surface of the lens or mirror
Focal Point
The point at which light rays from a mirror or lens intersec
Force
(vector; N) A push or pull that causes an object to accelerate
Force Diagram
A diagram displaying all of the forces acting on an object
Forced Vibrations
The vibrations produced in an object connected to another vibrating object, with the effect of amplifying the vibrations of the first object
Free-Body Diagram
Another name for force diagram
Frequency
(Scalar; Hz) The number of complete cycles of simple harmonic motion per unit time; the reciprocal of period; the number of wave cycles passing a fixed point per unit time
Friction
A retarding force between two objects that inhibits motion
Galvanometer
A device used to measure electrical current
Gaussian Surface
An imaginary surface-enclosing charge used to calculate the electric field at points on the surface using Gauss’s law
General Relativity
The theory of mechanics that treats gravitational fields as equivalent to relative acceleration and introduces the notion that mass curves space and time
Generator
A device that converts mechanical energy into electrical energy
Half-Life
The time required for half of a radioactive sample to decay
Heat Capacity
(Scalar; J/K) The amount of heat energy required to change the temperature of an object by one degree
Heat Fusion
(Scalar; J) The heat that must be added per unit mass for a phase change of a substance between solid and liquid states. For a change from liquid to solid, the heat of fusion is released
Heat of Vaporization
(Scalar; J) The heat that must be added per unit mass for a phase change of a substance between liquid and gas states. For a change from liquid to solid, the heat of vaporization is released
Henry
(H) The SI unit of measurement of inductance, equivalent to V-s/A
Hertz
(Hz) The SI unit of measurement of frequency; equivalent to s^-1
Ideal Gas
A collection of identical, infinitesimally small particles that interact only by elastic collisions
Impulse
(Vector; N-s) The product of the average force acting on an object and the time over which it acts
Index of Refraction
(Scalar) An intrinsic property of a transparent substance, which measures the speed of light in the material compared to the speed of light in a vacuum
Inductance
(Scalar; H) A property of a circuit that is the proportionality constant between the rate of change of the current in that circuit and the emf that this changing current produces
Induction
The process by which electromotive forces are generated in a circuit due to changes in a magnetic field
Inelastic Collision
A collision between objects in which the kinetic energy changes, for example, due to deformation or frictional loss
Inertial Frame
A set of coordinates that is not accelerating
Insulator
A material through which electrical charges cannot flow
Intensity
(Scalar; W/m2) The amount of energy carried by a wave across a unit area in a unit time
Isobaric
At constant pressure
Isochoric
At constant volume
Isothermal
At constant temperature
Isotopes
Atoms with nuclei possessing the same number of protons but different numbers of neutrons
Joule
(J) The SI unit of measurement of energy; equivalent to kg-m2/s2
Kelvin
(K) The SI unit of measurement of temperature
Kilogram
(kg) The SI unit of measurement of mass
Kinetic Energy
(Scalar; J) The energy of an object in motion
Kinetic Friction
A friction that acts to resist motion of an object that is already moving
Kinetic Theory of Gases
A model of an ideal gas that treats it as a collection of molecules undergoing motion according to Newton’s laws of classical mechanics and predicts macroscopic quantities such as pressure and temperature in terms of molecular properties, such as the velocity of the molecules
Latent Heat
(Scalar; J/kg) The heat required for a phase change of a substance per unit mass
Law of Conservation of Momentum
Fundamental law of physics which states that the linear momentum of a system does not change unless an external force acts upon the system
Line Spectrum
The specific wavelengths of light absorbed and emitted by a gas. The line spectrum is different for each type of gas
Linear Momentum
(Vector; kg-m/s2) The product of mass and velocity
Lines of Force
A pictorial representation of an electric field or magnetic field or any other vector field. Also called field lines
Longitudinal Wave
A wave in which points on the wave move parallel to the direction of wave propagation
Lorentz Contraction
The effect that an observer moving with respect to a given object will find the object to be shortened compared with the measurement by an observer at rest relative to the object
Loudness
(Scalar; decibels) The intensity of a sound wave compared to a set standard, namely, the lowest threshold of human hearing
Magnetic Field
(Vector; T) The force felt by a unit positive test charge moving through space, due to the influence of magnets or moving charges. Magnetic fields are produced by moving charges
Magnetic Flux
(Scalar; T-m2) The total sum of magnetic field vectors passing perpendicularly through a surface. According to Faraday’s law, the rate of change of the magnetic flux through a surface is proportional to electromotive force generated on the closed loop containing the surface
Mass
(Scalar; kg) The intrinsic property of matter that causes it to resist acceleration
Mass Spectrometer
An instrument that separates ionized atoms or molecules based upon their ratio of charge to mass
