Symbols and Abbreviations

Units are denoted by an asterisk. Dimensions and values of constants are in parentheses.

See also the NIST pages on constants, units and uncertainty.

a, Aacceleration (length / time 2), atomic mass (total number of protons and neutrons in an atom)
AAmperes* (electric current = C / s), Angstroms* (length = 10 - 10 m), amplitude (length)
bintercept of a linear graph, drag coefficient (mass / time)
Bmagnetic field (force / current)
cspeed of light (2.998 x 10 8 m / s), specific heat (energy / mass x temperature), concentration (number / volume), speed of sound
calcalories* (energy = 4.186 J)
cccubic centimeter
c ggroup velocity
c pphase velocity
CCelsius* (temperature), Coulombs* (electric charge), capacitance (charge / electric potential), heat capacity (energy / temperature), concentration
Calkilocalories* (energy)
CiCurie* (unit of radiation, equivalent to 3.7 x 10 10 decays / s)
ddistance
Ddiffusion constant (area / time)
dbdecibels (relative intensity)
eelectron, charge of an electron (1.602 x 10 - 19 C)
eVelectron Volts* (energy = 1.602 x 10 - 19 J)
Eenergy (force x length, mass x velocity 2), electric field (force / charge)
ffrequency (1 / time), focal length
f, Fforce (mass x acceleration)
Fflow (volume / time), Farads* (capacitance = C / V), Fermi* (length = 10 - 15 m)
ggrams* (mass), acceleration due to gravity (9.81 m / s 2); sometimes centrifugal acceleration
GNewton's constant (6.673 x 10 - 11 N m 2 / kg 2), Gauss* (magnetic field =
10 - 4 T), free energy
hheight, Planck's constant (angular momentum = 6.626 x 10 - 34 J s), latent heat (energy / mass)
hrhours* (time = 3600 s)
Henthalpy (energy)
HzHertz (1 / s)
Imoment of inertia (mass x length 2), current (charge / time), intensity (power / area), image distance
JJoules* (energy = N m), flux (number / area time)
kBoltzmann constant (1.381 x 10 - 23 J / K), spring constant (force / length), thermal conductivity (power / length temperature), wave number (1 / length)
(1 / length)
Kkinetic energy, Kelvin* (temperature = C + 273.15)
llength, liters* (volume = 1000 cc), orbital quantum number (dimensionless, denotes angular momentum), mean free path (length)
lbpounds* (weight; 1 kg weighs 2.2 lb)
Langular momentum (momentum x length, moment of inertia x angular velocity)
mmass, meters* (length), slope of a linear graph, magnetic moment (current x area), magnetic quantum number (dimensionless, denotes orientation of angular momentum)
memass of electron (9.109 x 10 - 31 kg)
mnmass of neutron (1.675 x 10 - 27 kg)
mpmass of proton (1.673 x 10 - 27 kg)
mimiles* (length = 1.61 km)
minminutes* (time = 60 s)
mmHgmillimeters of mercury (pressure = 1333 dynes / cm 2)
Mmolecular weight (mass / mol), magnification (dimensionless)
nnumbers of mols (dimensionless), number of loops (dimensionless), neutron, principle quantum number (dimensionless, denotes energy level), index of refraction (dimensionless)
NNewtons* (force = kg m / s 2), number of particles, neutron number (number of neutrons in an atom)
N AAvogadro's number (dimensionless number of objects in a mol = 6.022 x 10 23)
Oobject distance
pproton
Pmomentum (mass x velocity), pressure (force / area), power (energy / time)
PaPascals* (pressure = N / m 2)
q, Qcharge
Qheat (energy)
rradius (length), distance, rate (velocity)
Rresistance (potential / current), gas constant (8.31 J / mol K)
ReReynolds number (dimensionless)
sseconds*, sedimentation coefficient (time), spin quantum number (dimensionless), lens strength (1 / length)
Sentropy (energy / temperature)
ttime
TTesla* (magnetic field = N / A), temperature
Upotential energy (mechanical, elastic, electrical), internal energy
vvelocity (length / time), specific volume (volume / mass)
Vvelocity, volume (length 3), electric potential (electric field x length), voltage, Volts* (N m / C)
WWatts* (power = J / s), weight (force), work (energy)
x, Xhorizontal position
y, Yvertical position or depth position in 3D problems
z, Zvertical position in 3D problems, atomic number (number of protons in an atom), valence

aalphaangular acceleration (radians / time 2), Helium nucleus (2 p + 2 n)
bbetaelectron
Ddeltafinite change
d"d"instantaneous rate of change
eepsilonelectrical permittivity (e0 = 8.854 x 10 - 12 F / m), emissivity
(dimensionless), efficiency (dimensionless)
fphiangle
ggammaelectromagnetic radiation, photon
hetaviscosity (Poise = dyne x s / cm 2 = g / cm x s)
kkappadielectric coefficient (dimensionless)
llambdawavelength
mmumagnetic permeability (m0 = 4 p x 10 - 7 T m / A)
nnufrequency or rate of revolution (1 / time)
qthetaangle, angular position
rrhodensity (mass / volume), resistivity (resistance x length)
ssigmaStefan-Boltzmann constant (5.67 x 10 - 8 W / m 2 K 4)
Ssigmasummation
ttautorque (force x length, moment of inertia x angular acceleration), radioactive half-life
womegaangular velocity or angular frequency (radians / time)
WomegaOhms* (resistance = volt / ampere)



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1996, Kenneth R. Koehler. All Rights Reserved. This document may be freely reproduced provided that this copyright notice is included.

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