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

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

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

°C | Celsius degree |

°F | Fahrenheit degree |

// | parallel |

⊥ | perpendicular |

[latex]\propto\\[/latex] | 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 |

[latex]\displaystyle\gamma=\frac{1}{\sqrt{1-\frac{v^2}{c^2}}}\\[/latex] | 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 |

[latex]\overline{\rho}_{\text{obj}}\\[/latex] | average density of an object |

[latex]\displaystyle\frac{\rho}{\rho_{\text{w}}}\\[/latex] | 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 |

[latex]\overline{B}\\[/latex] | 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 |

[latex]\displaystyle\frac{\text{BE}}{A}\\[/latex] | 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 |

[latex]\overline{G}\\[/latex] | 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 |

[latex]\displaystyle\frac{\text{J}}{\Psi}\\[/latex] | 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 |

[latex]\overline{\text{KE}}\\[/latex] | 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) |

[latex]m\left({^{A}\text{X}}\right)\\[/latex] | 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 |

[latex]\overline{R}\\[/latex] | 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 |

[latex]\overline{\mathbf{v}}\\[/latex] | 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 |

[latex]^A_Z\text{X}_N\\[/latex] | 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 |