Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....  # Notation

Δ"change in;" the value of a variable afterwards minus its value before
Δxa distance, or more precisely a change in x, which may be less than the distance traveled; its plus or minus sign indicates direction
Δta duration of time
Δrthe vector whose components are Δx, Δy, and Δz
λwavelength (Greek letter lambda)
µsthe coefficient of static friction; the constant of proportionality between the maximum static frictional force and the normal force; depends on what types of surfaces are involved
µkthe coefficient of kinetic friction; the constant of proportionality between the kinetic frictional force and the normal force; depends on what types of surfaces are involved
νThe Greek letter ν, nu, is used in many books for frequency.
νa neutrino
ν[bar]an antineutrino
ψthe wavefunction of an electron
ωThe Greek letter ω, omega, is often used as an abbreviation for 2π.
Ωunits of ohms
θfthe focal angle, defined as 1/f
θothe object angle, defined as 1/do
θithe image angle, defined as 1/di
\$the magnitude of the L vector, divided by h[bar]
\$zthe z component of the L vector, divided by h[bar]; this is the standard notation in nuclear physics, but not in atomic physics
aacceleration
ax, ay, azthe x, y, and z components of an object's acceleration; the rates of change of vx, vy, and vz
Aamplitude
Amass number (N+Z)
Aunits of amperes
Aa vector with components Ax, Ay, and Az
§§Ahandwritten notation for a vector
|A|the magnitude of vector A
arradial acceleration; the component of the acceleration vector along the in-out direction
attangential acceleration; the component of the acceleration vector tangent to the circle
Bthe magnetic field
cmcenter of mass, as in xcm, acm, etc.
Dan electric dipole moment
dithe distance of the image from the mirror
dothe distance of the object from the mirror (technically from the plane tangent to the center of the mirror, although this seldom matters much for a mirror whose curve is shallow)
d,p,mother notations for the electric dipole moment
Dmmagnetic dipole moment
Eenergy
Ethe electric field
ethe quantum of charge
e-an electron
e+an antielectron; just like an electron, but with positive charge
eVa unit of energy, equal to e multiplied by 1 volt; 1.6x10 -19 joules
fthe focal length
ffrequency
fresthe natural (resonant) frequency of a vibrating system, i.e. the frequency at which it would vibrate if it was simply kicked and left alone
Fka kinetic frictional force
FNa normal force
Fsa static frictional force
FWweight
gthe acceleration of objects in free fall; the strength of the local gravitational field
gthe gravitational field
Gthe constant of proportionality in Newton's law of gravity; the gravitational force of attraction between two 1-kg spheres at a center-to-center distance of 1 m
h[bar]Planck's constant divided by 2π: h/2π
Icurrent
Jjoules, the SI unit of energy
K or Talternative symbols for kinetic energy, used in the scientific literature and in most advanced textbooks
kthe slope of the graph of F versus x, where F is the total force acting on an object and x is the object's position; For a spring, this is known as the spring constant.
kthe spring constant; the constant of proportionality between the force exerted on an object and the amount by which the object is lengthened or compressed
KEkinetic energy
Langular momentum
Lthe angular momentum vector of a particle, not including its spin
m\$a less obvious notation for \$z, standard in atomic physics
msa less obvious notation for sz, standard in atomic physics
Mthe magnification of an image
Mathe angular magnification of an image
na neutron
nthe index of refraction
nthe number of radial nodes in the wavefunction, including the one at r = ∞
Nnumber of neutrons in a nucleus
pa proton
pthe momentum vector
pprobability
Ppower
PEpotential energy
Q or ΔQthe amount of heat transferred into or out of an object
qcharge
Qthe quality factor
Rresistance
rthe vector whose components are x, y, and z
sthe magnitude of the spin angular momentum vector, divided by h[bar]
szthe z component of the spin angular momentum vector, divided by h[bar]; this is the standard notation in nuclear physics, but not in atomic physics
Tperiod
Tthe time required for a rigidly rotating body to complete one rotation
ta point in time, a clock reading
ttorque
t1/2half-life
U or Vsymbols used for potential energy in the scientific literature and in most advanced textbooks
vvelocity
vABthe velocity of object A relative to object B
vx, vy, vzthe x, y, and z components of an object's velocity; the rates of change of the object's x, y, and z coordinates
Vvoltage
Vunits of volts
Wwatts, the SI unit of power; equivalent to J/s
Wwork
xa point in space
x, y, zan object's positions along the x, y, and z axes
Zatomic number (number of protons in a nucleus) is proportional to
~on the order of, is on the order of
mmeter, the metric distance unit
kgkilogram, the metric unit of mass
ssecond, the metric unit of time
M-the metric prefix mega-, 106
k-the metric prefix kilo-, 103
m-the metric prefix milli-, 10-3
μ-the metric prefix micro-, 10-6
n-the metric prefix nano-, 10-9 (optional topic) unit vectors; the vectors with magnitude 1 lying along the x, y, and z axes a harder to remember notation for the unit vectors

Last Update: 2010-11-11