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HomeStudy GuidesPhysics

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The Nature of Science and Physics

Kinematics

Introduction to One-Dimensional KinematicsDisplacementVectors, Scalars, and Coordinate SystemsTime, Velocity, and SpeedVideo: One-Dimensional KinematicsAccelerationMotion Equations for Constant Acceleration in One DimensionProblem-Solving Basics for One-Dimensional KinematicsFalling ObjectsGraphical Analysis of One-Dimensional Motion

Two-Dimensional Kinematics

Dynamics: Force and Newton's Laws of Motion

Introduction to Dynamics: Newton's Laws of MotionDevelopment of Force ConceptNewton's First Law of Motion: InertiaNewton's Second Law of Motion: Concept of a SystemNewton's Third Law of Motion: Symmetry in ForcesVideo: Newton's LawsNormal, Tension, and Other Examples of ForcesProblem-Solving StrategiesFurther Applications of Newton's Laws of MotionExtended Topic: The Four Basic Forces—An Introduction

Further Applications of Newton's Laws: Friction, Drag, and Elasticity

Uniform Circular Motion and Gravitation

Introduction to Uniform Circular Motion and GravitationRotation Angle and Angular VelocityCentripetal AccelerationCentripetal ForceFictitious Forces and Non-inertial Frames: The Coriolis ForceNewton's Universal Law of GravitationVideo: GravitationSatellites and Kepler's Laws: An Argument for Simplicity

Work, Energy, and Energy Resources

Introduction to Work, Energy, and Energy ResourcesWork: The Scientific DefinitionKinetic Energy and the Work-Energy TheoremGravitational Potential EnergyVideo: Potential and Kinetic EnergyConservative Forces and Potential EnergyNonconservative ForcesConservation of EnergyPowerWork, Energy, and Power in HumansWorld Energy Use

Linear Momentum and Collisions

Rotational Motion and Angular Momentum

Introduction to Rotational Motion and Angular MomentumAngular AccelerationKinematics of Rotational MotionVideo: Rotational MotionDynamics of Rotational Motion: Rotational InertiaRotational Kinetic Energy: Work and Energy RevisitedAngular Momentum and Its ConservationVideo: Angular MomentumCollisions of Extended Bodies in Two DimensionsGyroscopic Effects: Vector Aspects of Angular Momentum

Statics and Torque

Fluid Statics

Introduction to Fluid StaticsWhat Is a Fluid?DensityPressureVariation of Pressure with Depth in a FluidPascal's PrincipleGauge Pressure, Absolute Pressure, and Pressure MeasurementArchimedes' PrincipleVideo: BuoyancyCohesion and Adhesion in Liquids: Surface Tension and Capillary ActionPressures in the Body

Fluid Dynamics and Its Biological and Medical Applications

Introduction to Fluid Dynamics and Biological and Medical ApplicationsFlow Rate and Its Relation to VelocityBernoulli's EquationVideo: Fluid FlowThe Most General Applications of Bernoulli's EquationViscosity and Laminar Flow; Poiseuille's LawThe Onset of TurbulenceMotion of an Object in a Viscous FluidMolecular Transport Phenomena: Diffusion, Osmosis, and Related Processes

Temperature, Kinetic Theory, and the Gas Laws

Heat and Heat Transfer Methods

Thermodynamics

Introduction to ThermodynamicsThe First Law of ThermodynamicsThe First Law of Thermodynamics and Some Simple ProcessesIntroduction to the Second Law of Thermodynamics: Heat Engines and Their EfficiencyCarnot's Perfect Heat Engine: The Second Law of Thermodynamics RestatedApplications of Thermodynamics: Heat Pumps and RefrigeratorsEntropy and the Second Law of Thermodynamics: Disorder and the Unavailability of EnergyStatistical Interpretation of Entropy and the Second Law of Thermodynamics: The Underlying Explanation

Oscillatory Motion and Waves

Introduction to Oscillatory Motion and WavesHooke's Law: Stress and Strain RevisitedPeriod and Frequency in OscillationsSimple Harmonic Motion: A Special Periodic MotionVideo: Harmonic MotionThe Simple PendulumEnergy and the Simple Harmonic OscillatorUniform Circular Motion and Simple Harmonic MotionDamped Harmonic MotionForced Oscillations and ResonanceWavesSuperposition and InterferenceEnergy in Waves: Intensity

Physics of Hearing

In this glossary, key symbols and notation are briefly defined.

### Licenses and Attributions

Symbol | Definition |
---|---|

$\overline{\text{any symbol}}\\$ |
average (indicated by a bar over a symbol—e.g., $\overline{v}\\$ is average velocity) |

°C | Celsius degree |

°F | Fahrenheit degree |

// | parallel |

⊥ | perpendicular |

$\propto\\$ |
proportional to |

± | plus or minus |

0 | zero as a subscript denotes an initial value |

α | alpha rays |

α | angular acceleration |

α | temperature coefficient(s) of resistivity |

β | beta rays |

β | sound level |

β | volume coefficient of expansion |

β^{−} |
electron emitted in nuclear beta decay |

β^{+} |
positron decay |

γ | gamma rays |

γ | surface tension |

$\displaystyle\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}\\$ |
a constant used in relativity |

Δ | change in whatever quantity follows |

δ | uncertainty in whatever quantity follows |

ΔE |
change in energy between the initial and final orbits of an electron in an atom |

ΔE |
uncertainty in energy |

Δm |
difference in mass between initial and final products |

ΔN |
number of decays that occur |

Δp |
change in momentum |

Δp |
uncertainty in momentum |

ΔPE_{g} |
change in gravitational potential energy |

Δθ |
rotation angle |

Δs |
distance traveled along a circular path |

Δt |
uncertainty in time |

Δt_{0} |
proper time as measured by an observer at rest relative to the process |

ΔV |
potential difference |

Δx |
uncertainty in position |

ε_{0} |
permittivity of free space |

η |
viscosity |

θ |
angle between the force vector and the displacement vector |

θ |
angle between two lines |

θ |
contact angle |

θ |
direction of the resultant |

θ_{b} |
Brewster's angle |

θ_{c} |
critical angle |

κ |
dielectric constant |

λ |
decay constant of a nuclide |

λ |
wavelength |

λ_{n} |
wavelength in a medium |

μ_{0} |
permeability of free space |

μ_{k} |
coefficient of kinetic friction |

μ_{s} |
coefficient of static friction |

v_{e} |
electron neutrino |

π^{+} |
positive pion |

π^{−} |
negative pion |

π^{0} |
neutral pion |

ρ |
density |

ρ_{c} |
critical density, the density needed to just halt universal expansion |

ρ_{fl} |
fluid density |

$\overline{\rho}_{\text{obj}}\\$ |
average density of an object |

$\displaystyle\frac{\rho}{\rho_{\text{w}}}\\$ |
specific gravity |

τ |
characteristic time constant for a resistance and inductance (RL) or resistance and capacitance (RC) circuit |

τ |
characteristic time for a resistor and capacitor (RC) circuit |

τ |
torque |

Υ | upsilon meson |

Φ | magnetic flux |

ϕ |
phase angle |

Ω | ohm (unit) |

ω |
angular velocity |

A | ampere (current unit) |

A |
area |

A |
cross-sectional area |

A |
total number of nucleons |

a |
acceleration |

a_{B} |
Bohr radius |

a_{c} |
centripetal acceleration |

a_{t} |
tangential acceleration |

AC | alternating current |

AM | amplitude modulation |

atm | atmosphere |

B |
baryon number |

B |
blue quark color |

$\overline{B}\\$ |
antiblue (yellow) antiquark color |

b |
quark flavor bottom or beauty |

B |
bulk modulus |

B |
magnetic field strength |

B_{int} |
electron’s intrinsic magnetic field |

B_{orb} |
orbital magnetic field |

BE | binding energy of a nucleus—it is the energy required to completely disassemble it into separate protons and neutrons |

$\displaystyle\frac{\text{BE}}{A}\\$ |
binding energy per nucleon |

Bq | becquerel—one decay per second |

C |
capacitance (amount of charge stored per volt) |

C |
coulomb (a fundamental SI unit of charge) |

C_{p} |
total capacitance in parallel |

C_{s} |
total capacitance in series |

CG | center of gravity |

CM | center of mass |

c |
quark flavor charm |

c |
specific heat |

c |
speed of light |

Cal | kilocalorie |

cal | calorie |

COP_{hp} |
heat pump’s coefficient of performance |

COP_{ref} |
coefficient of performance for refrigerators and air conditioners |

cosθ |
cosine |

cotθ |
cotangent |

cscθ |
cosecant |

D |
diffusion constant |

d |
displacement |

d |
quark flavor down |

dB | decibel |

d_{i} |
distance of an image from the center of a lens |

d_{o} |
distance of an object from the center of a lens |

DC | direct current |

E |
electric field strength |

ε |
emf (voltage) or Hall electromotive force |

emf | electromotive force |

E |
energy of a single photon |

E |
nuclear reaction energy |

E |
relativistic total energy |

E |
total energy |

E_{0} |
ground state energy for hydrogen |

E_{0} |
rest energy |

EC | electron capture |

E_{cap} |
energy stored in a capacitor |

Eff |
efficiency—the useful work output divided by the energy input |

Eff_{C} |
Carnot efficiency |

E_{in} |
energy consumed (food digested in humans) |

E_{ind} |
energy stored in an inductor |

E_{out} |
energy output |

e |
emissivity of an object |

e^{+} |
antielectron or positron |

eV | electron volt |

F | farad (unit of capacitance, a coulomb per volt) |

F | focal point of a lens |

F |
force |

F |
magnitude of a force |

F |
restoring force |

F_{B} |
buoyant force |

F_{c} |
centripetal force |

F_{i} |
force input |

F_{net} |
net force |

F_{o} |
force output |

FM | frequency modulation |

f |
focal length |

f |
frequency |

f_{0} |
resonant frequency of a resistance, inductance, and capacitance (RLC) series circuit |

f_{0} |
threshold frequency for a particular material (photoelectric effect) |

f_{1} |
fundamental |

f_{2} |
first overtone |

f_{3} |
second overtone |

f_{B} |
beat frequency |

f_{k} |
magnitude of kinetic friction |

f_{s} |
magnitude of static friction |

G |
gravitational constant |

G |
green quark color |

$\overline{G}\\$ |
antigreen (magenta) antiquark color |

g |
acceleration due to gravity |

g |
gluons (carrier particles for strong nuclear force) |

h |
change in vertical position |

h |
height above some reference point |

h |
maximum height of a projectile |

h |
Planck's constant |

hf |
photon energy |

h_{i} |
height of the image |

h_{o} |
height of the object |

I |
electric current |

I |
intensity |

I |
intensity of a transmitted wave |

I |
moment of inertia (also called rotational inertia) |

I_{0} |
intensity of a polarized wave before passing through a filter |

I_{ave} |
average intensity for a continuous sinusoidal electromagnetic wave |

I_{rms} |
average current |

J | joule |

$\displaystyle\frac{\text{J}}{\Psi}\\$ |
Joules/psi meson |

K | kelvin |

k |
Boltzmann constant |

k |
force constant of a spring |

K_{α} |
x rays created when an electron falls into an n = 1 shell vacancy from the n = 3 shell |

K_{β} |
x rays created when an electron falls into an n = 2 shell vacancy from the n = 3 shell |

kcal | kilocalorie |

KE | translational kinetic energy |

KE + PE | mechanical energy |

KE_{e} |
kinetic energy of an ejected electron |

KE_{rel} |
relativistic kinetic energy |

KE_{rot} |
rotational kinetic energy |

$\overline{\text{KE}}\\$ |
thermal energy |

kg | kilogram (a fundamental SI unit of mass) |

L |
angular momentum |

L | liter |

L |
magnitude of angular momentum |

L |
self-inductance |

ℓ |
angular momentum quantum number |

L_{α} |
x rays created when an electron falls into an n = 2 shell from the n = 3 shell |

L_{e} |
electron total family number |

L_{μ} |
muon family total number |

L_{τ} |
tau family total number |

L_{f} |
heat of fusion |

L and _{f}L_{v} |
latent heat coefficients |

L_{orb} |
orbital angular momentum |

L_{s} |
heat of sublimation |

L_{v} |
heat of vaporization |

L_{z} |
z-component of the angular momentum |

M |
angular magnification |

M |
mutual inductance |

m | indicates metastable state |

m |
magnification |

m |
mass |

m |
mass of an object as measured by a person at rest relative to the object |

m | meter (a fundamental SI unit of length) |

m |
order of interference |

m |
overall magnification (product of the individual magnifications) |

$m\left({^{A}\text{X}}\right)\\$ |
atomic mass of a nuclide |

MA | mechanical advantage |

m_{e} |
magnification of the eyepiece |

m_{e} |
mass of the electron |

m_{ℓ} |
angular momentum projection quantum number |

m_{n} |
mass of a neutron |

m_{o} |
magnification of the objective lens |

mol | mole |

m_{p} |
mass of a proton |

m_{s} |
spin projection quantum number |

N |
magnitude of the normal force |

N | newton |

N |
normal force |

N |
number of neutrons |

n |
index of refraction |

n |
number of free charges per unit volume |

N_{A} |
Avogadro's number |

N_{r} |
Reynolds number |

N · m | newton-meter (work-energy unit) |

N · m | newtons times meters (SI unit of torque) |

OE | other energy |

P |
power |

P |
power of a lens |

P |
pressure |

p |
momentum |

p |
momentum magnitude |

p |
relativistic momentum |

p_{tot} |
total momentum |

p_{tot} |
total momentum some time later |

P_{abs} |
absolute pressure |

P_{atm} |
atmospheric pressure |

P_{atm} |
standard atmospheric pressure |

PE | potential energy |

PE_{el} |
elastic potential energy |

PE_{elec} |
electric potential energy |

PE_{s} |
potential energy of a spring |

P_{g} |
gauge pressure |

P_{in} |
power consumption or input |

P_{out} |
useful power output going into useful work or a desired, form of energy |

Q |
latent heat |

Q |
net heat transferred into a system |

Q |
flow rate—volume per unit time flowing past a point |

+Q |
positive charge |

−Q |
negative charge |

q |
electron charge |

q_{p} |
charge of a proton |

q |
test charge |

QF | quality factor |

R |
activity, the rate of decay |

R |
radius of curvature of a spherical mirror |

R |
red quark color |

$\overline{R}\\$ |
antired (cyan) quark color |

R |
resistance |

R | resultant or total displacement |

R |
Rydberg constant |

R |
universal gas constant |

r |
distance from pivot point to the point where a force is applied |

r |
internal resistance |

r⊥ |
perpendicular lever arm |

r |
radius of a nucleus |

r |
radius of curvature |

r |
resistivity |

r or rad | radiation dose unit |

rem | roentgen equivalent man |

rad | radian |

RBE | relative biological effectiveness |

RC |
resistor and capacitor circuit |

rms | root mean square |

r_{n} |
radius of the nth H-atom orbit |

R_{p} |
total resistance of a parallel connection |

R_{s} |
total resistance of a series connection |

R_{s} |
Schwarzschild radius |

S |
entropy |

S |
intrinsic spin (intrinsic angular momentum) |

S |
magnitude of the intrinsic (internal) spin angular momentum |

S |
shear modulus |

S |
strangeness quantum number |

s |
quark flavor strange |

s | second (fundamental SI unit of time) |

s |
spin quantum number |

s |
total displacement |

secθ |
secant |

sinθ |
sine |

s_{z} |
z-component of spin angular momentum |

T |
period—time to complete one oscillation |

T |
temperature |

T_{c} |
critical temperature—temperature below which a material becomes a superconductor |

T |
tension |

T | tesla (magnetic field strength B) |

t |
quark flavor top or truth |

t |
time |

t_{1/2} |
half-life—the time in which half of the original nuclei decay |

tanθ |
tangent |

U |
internal energy |

u |
quark flavor up |

u | unified atomic mass unit |

u |
velocity of an object relative to an observer |

u′ |
velocity relative to another observer |

V |
electric potential |

V |
terminal voltage |

V | volt (unit) |

V |
volume |

v |
relative velocity between two observers |

v |
speed of light in a material |

v |
velocity |

$\overline{\mathbf{v}}\\$ |
average fluid velocity |

V − _{B}V_{A} |
change in potential |

v_{d} |
drift velocity |

V_{p} |
transformer input voltage |

V_{rms} |
rms voltage |

V_{s} |
transformer output voltage |

v_{tot} |
total velocity |

v_{w} |
propagation speed of sound or other wave |

v_{w} |
wave velocity |

W |
work |

W |
net work done by a system |

W | watt |

w |
weight |

w_{fl} |
weight of the fluid displaced by an object |

W_{c} |
total work done by all conservative forces |

W_{nc} |
total work done by all nonconservative forces |

W_{out} |
useful work output |

X |
amplitude |

X | symbol for an element |

$^A_Z\text{X}_N\\$ |
notation for a particular nuclide |

x |
deformation or displacement from equilibrium |

x |
displacement of a spring from its undeformed position |

x |
horizontal axis |

X_{C} |
capacitive reactance |

X_{L} |
inductive reactance |

x_{rms} |
root mean square diffusion distance |

y |
vertical axis |

Y |
elastic modulus or Young's modulus |

Z |
atomic number (number of protons in a nucleus) |

Z |
impedance |