College Physics for AP® Courses

# D | Glossary of Key Symbols and Notation

College Physics for AP® CoursesD | Glossary of Key Symbols and Notation

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

Symbol Definition
$any symbol ¯ any symbol ¯ size 12{ {overline {"any"" symbol"}} } {}$ average (indicated by a bar over a symbol—e.g., $v¯v¯ size 12{ {overline {v}} } {}$ is average velocity)
$° C ° C size 12{°C} {}$ Celsius degree
$° F ° F size 12{°F} {}$ Fahrenheit degree
$// // size 12{"//"} {}$ parallel
$⊥ ⊥ size 12{ ortho } {}$ perpendicular
$∝ ∝ size 12{ prop } {}$ proportional to
$± ± size 12{ +- {}} {}$ plus or minus
$0 0 size 12{ {} rSub { size 8{0} } } {}$ zero as a subscript denotes an initial value
$α α size 12{α} {}$ alpha rays
$α α size 12{α} {}$ angular acceleration
$α α size 12{α} {}$ temperature coefficient(s) of resistivity
$β β size 12{β} {}$ beta rays
$β β size 12{β} {}$ sound level
$β β size 12{β} {}$ volume coefficient of expansion
$β − β − size 12{β rSup { size 8{ - {}} } } {}$ electron emitted in nuclear beta decay
$β + β + size 12{β rSup { size 8{+{}} } } {}$ positron decay
$γ γ size 12{γ} {}$ gamma rays
$γ γ size 12{γ} {}$ surface tension
$γ = 1 / 1 − v 2 / c 2 γ = 1 / 1 − v 2 / c 2 size 12{γ= {1} slash { sqrt {1 - {v rSup { size 8{2} } } slash {c rSup { size 8{2} } } } } } {}$ a constant used in relativity
$Δ Δ size 12{Δ} {}$ change in whatever quantity follows
$δ δ size 12{δ} {}$ uncertainty in whatever quantity follows
$ΔE ΔE size 12{ΔE} {}$ change in energy between the initial and final orbits of an electron in an atom
$ΔE ΔE size 12{ΔE} {}$ uncertainty in energy
$Δm Δm size 12{Δm} {}$ difference in mass between initial and final products
$ΔN ΔN size 12{ΔN} {}$ number of decays that occur
$Δp Δp size 12{Δp} {}$ change in momentum
$Δp Δp size 12{Δp} {}$ uncertainty in momentum
$Δ PE g Δ PE g size 12{Δ"PE" rSub { size 8{g} } } {}$ change in gravitational potential energy
$Δθ Δθ size 12{Δθ} {}$ rotation angle
$Δs Δs size 12{Δs} {}$ distance traveled along a circular path
$Δt Δt size 12{Δt} {}$ uncertainty in time
$Δt 0 Δt 0 size 12{Δt rSub { size 8{0} } } {}$ proper time as measured by an observer at rest relative to the process
$ΔV ΔV size 12{ΔV} {}$ potential difference
$Δx Δx size 12{Δx} {}$ uncertainty in position
$ε 0 ε 0 size 12{ε rSub { size 8{0} } } {}$ permittivity of free space
$η η size 12{η} {}$ viscosity
$θ θ size 12{θ} {}$ angle between the force vector and the displacement vector
$θ θ size 12{θ} {}$ angle between two lines
$θ θ size 12{θ} {}$ contact angle
$θ θ size 12{θ} {}$ direction of the resultant
$θ b θ b size 12{θ rSub { size 8{b} } } {}$ Brewster's angle
$θ c θ c size 12{θ rSub { size 8{c} } } {}$ critical angle
$κ κ size 12{κ} {}$ dielectric constant
$λ λ size 12{λ} {}$ decay constant of a nuclide
$λ λ size 12{λ} {}$ wavelength
$λ n λ n size 12{λ rSub { size 8{n} } } {}$ wavelength in a medium
$μ 0 μ 0 size 12{μ rSub { size 8{0} } } {}$ permeability of free space
$μ k μ k size 12{μ rSub { size 8{k} } } {}$ coefficient of kinetic friction
$μ s μ s size 12{μ rSub { size 8{s} } } {}$ coefficient of static friction
$v e v e size 12{v rSub { size 8{e} } } {}$ electron neutrino
$π + π + size 12{π rSup { size 8{+{}} } } {}$ positive pion
$π − π − size 12{π rSup { size 8{ - {}} } } {}$ negative pion
$π 0 π 0 size 12{π rSup { size 8{0} } } {}$ neutral pion
$ρ ρ size 12{ρ} {}$ density
$ρ c ρ c size 12{ρ rSub { size 8{c} } } {}$ critical density, the density needed to just halt universal expansion
$ρ fl ρ fl size 12{ρ rSub { size 8{"fl"} } } {}$ fluid density
$ρ ¯ obj ρ ¯ obj size 12{ {overline {ρ}} rSub { size 8{"obj"} } } {}$ average density of an object
$ρ / ρ w ρ / ρ w size 12{ {ρ} slash {ρ rSub { size 8{w} } } } {}$ specific gravity
$τ τ size 12{τ} {}$ characteristic time constant for a resistance and inductance $(RL)(RL) size 12{ $$ital "RL"$$ } {}$ or resistance and capacitance $(RC)(RC) size 12{ $$ital "RC"$$ } {}$ circuit
$τ τ size 12{τ} {}$ characteristic time for a resistor and capacitor $(RC)(RC) size 12{ $$ital "RC"$$ } {}$ circuit
$τ τ size 12{τ} {}$ torque
$Υ Υ size 12{Υ} {}$ upsilon meson
$Φ Φ size 12{Φ} {}$ magnetic flux
$ϕ ϕ size 12{ϕ} {}$ phase angle
$Ω Ω size 12{ %OMEGA } {}$ ohm (unit)
$ω ω size 12{ω} {}$ angular velocity
$A A size 12{A} {}$ ampere (current unit)
$A A size 12{A} {}$ area
$A A size 12{A} {}$ cross-sectional area
$A A size 12{A} {}$ total number of nucleons
$a a size 12{a} {}$ acceleration
$a B a B size 12{a rSub { size 8{B} } } {}$ Bohr radius
$a c a c size 12{a rSub { size 8{c} } } {}$ centripetal acceleration
$a t a t size 12{a rSub { size 8{t} } } {}$ tangential acceleration
$AC AC size 12{"AC"} {}$ alternating current
$AM AM size 12{"AM"} {}$ amplitude modulation
$atm atm size 12{"atm"} {}$ atmosphere
$B B size 12{B} {}$ baryon number
$B B size 12{B} {}$ blue quark color
$B ¯ B ¯ size 12{ {overline {B}} } {}$ antiblue (yellow) antiquark color
$b b size 12{b} {}$ quark flavor bottom or beauty
$B B size 12{B} {}$ bulk modulus
$B B size 12{B} {}$ magnetic field strength
$B int B int size 12{B rSub { size 8{"int"} } } {}$ electron’s intrinsic magnetic field
$B orb B orb size 12{B rSub { size 8{"orb"} } } {}$ orbital magnetic field
$BE BE size 12{"BE"} {}$ binding energy of a nucleus—it is the energy required to completely disassemble it into separate protons and neutrons
$BE / A BE / A size 12{ {"BE"} slash {A} } {}$ binding energy per nucleon
$Bq Bq size 12{"Bq"} {}$ becquerel—one decay per second
$C C size 12{C} {}$ capacitance (amount of charge stored per volt)
$C C size 12{C} {}$ coulomb (a fundamental SI unit of charge)
$C p C p size 12{C rSub { size 8{p} } } {}$ total capacitance in parallel
$C s C s size 12{C rSub { size 8{s} } } {}$ total capacitance in series
$CG CG size 12{"CG"} {}$ center of gravity
$CM CM size 12{"CM"} {}$ center of mass
$c c size 12{c} {}$ quark flavor charm
$c c size 12{c} {}$ specific heat
$c c size 12{c} {}$ speed of light
$Cal Cal size 12{"Cal"} {}$ kilocalorie
$cal cal size 12{"cal"} {}$ calorie
$COP hp COP hp size 12{ ital "COP" rSub { size 8{"hp"} } } {}$ heat pump’s coefficient of performance
$COP ref COP ref size 12{ ital "COP" rSub { size 8{"ref"} } } {}$ coefficient of performance for refrigerators and air conditioners
$cos θ cos θ size 12{"cos"θ} {}$ cosine
$cot θ cot θ size 12{"cot"θ} {}$ cotangent
$csc θ csc θ size 12{"csc"θ} {}$ cosecant
$D D size 12{D} {}$ diffusion constant
$d d size 12{d} {}$ displacement
$d d size 12{d} {}$ quark flavor down
$dB dB size 12{"dB"} {}$ decibel
$d i d i size 12{d rSub { size 8{i} } } {}$ distance of an image from the center of a lens
$d o d o size 12{d rSub { size 8{o} } } {}$ distance of an object from the center of a lens
$DC DC size 12{"DC"} {}$ direct current
$E E size 12{E} {}$ electric field strength
$ε ε size 12{ε} {}$ emf (voltage) or Hall electromotive force
$emf emf size 12{"emf"} {}$ electromotive force
$E E size 12{E} {}$ energy of a single photon
$E E size 12{E} {}$ nuclear reaction energy
$E E size 12{E} {}$ relativistic total energy
$E E size 12{E} {}$ total energy
$E 0 E 0 size 12{E rSub { size 8{0} } } {}$ ground state energy for hydrogen
$E 0 E 0 size 12{E rSub { size 8{0} } } {}$ rest energy
$EC EC size 12{"EC"} {}$ electron capture
$E cap E cap size 12{E rSub { size 8{"cap"} } } {}$ energy stored in a capacitor
$Eff Eff size 12{ ital "Eff"} {}$ efficiency—the useful work output divided by the energy input
$Eff C Eff C size 12{ ital "Eff" rSub { size 8{C} } } {}$ Carnot efficiency
$E in E in size 12{E rSub { size 8{"in"} } } {}$ energy consumed (food digested in humans)
$E ind E ind size 12{E rSub { size 8{"ind"} } } {}$ energy stored in an inductor
$E out E out size 12{E rSub { size 8{"out"} } } {}$ energy output
$e e size 12{e} {}$ emissivity of an object
$e + e + size 12{e rSup { size 8{+{}} } } {}$ antielectron or positron
$eV eV size 12{"eV"} {}$ electron volt
$F F size 12{F} {}$ farad (unit of capacitance, a coulomb per volt)
$F F size 12{F} {}$ focal point of a lens
$F F size 12{F} {}$ force
$F F size 12{F} {}$ magnitude of a force
$F F size 12{F} {}$ restoring force
$F B F B size 12{F rSub { size 8{B} } } {}$ buoyant force
$F c F c size 12{F rSub { size 8{c} } } {}$ centripetal force
$F i F i size 12{F rSub { size 8{i} } } {}$ force input
$F net F net size 12{F rSub { size 8{"net"} } } {}$ net force
$F o F o size 12{F rSub { size 8{o} } } {}$ force output
$FM FM size 12{"FM"} {}$ frequency modulation
$f f size 12{f} {}$ focal length
$f f size 12{f} {}$ frequency
$f 0 f 0 size 12{f rSub { size 8{0} } } {}$ resonant frequency of a resistance, inductance, and capacitance $(RLC)(RLC) size 12{ $$ital "RLC"$$ } {}$ series circuit
$f 0 f 0 size 12{f rSub { size 8{0} } } {}$ threshold frequency for a particular material (photoelectric effect)
$f 1 f 1 size 12{f rSub { size 8{1} } } {}$ fundamental
$f 2 f 2 size 12{f rSub { size 8{2} } } {}$ first overtone
$f 3 f 3 size 12{f rSub { size 8{3} } } {}$ second overtone
$f B f B size 12{f rSub { size 8{B} } } {}$ beat frequency
$f k f k size 12{f rSub { size 8{k} } } {}$ magnitude of kinetic friction
$f s f s size 12{f rSub { size 8{s} } } {}$ magnitude of static friction
$G G size 12{G} {}$ gravitational constant
$G G size 12{G} {}$ green quark color
$G ¯ G ¯ size 12{ {overline {G}} } {}$ antigreen (magenta) antiquark color
$g g size 12{g} {}$ acceleration due to gravity
$g g size 12{g} {}$ gluons (carrier particles for strong nuclear force)
$h h size 12{h} {}$ change in vertical position
$h h size 12{h} {}$ height above some reference point
$h h size 12{h} {}$ maximum height of a projectile
$h h size 12{h} {}$ Planck's constant
$hf hf size 12{ ital "hf"} {}$ photon energy
$h i h i size 12{h rSub { size 8{i} } } {}$ height of the image
$h o h o size 12{h rSub { size 8{o} } } {}$ height of the object
$I I size 12{I} {}$ electric current
$I I size 12{I} {}$ intensity
$I I size 12{I} {}$ intensity of a transmitted wave
$I I size 12{I} {}$ moment of inertia (also called rotational inertia)
$I 0 I 0 size 12{I rSub { size 8{0} } } {}$ intensity of a polarized wave before passing through a filter
$I ave I ave size 12{I rSub { size 8{"ave"} } } {}$ average intensity for a continuous sinusoidal electromagnetic wave
$I rms I rms size 12{I rSub { size 8{"rms"} } } {}$ average current
$J J size 12{J} {}$ joule
$J / Ψ J / Ψ size 12{ {J} slash {Ψ} } {}$ Joules/psi meson
$K K size 12{K} {}$ kelvin
$k k size 12{k} {}$ Boltzmann constant
$k k size 12{k} {}$ force constant of a spring
$K α K α size 12{K rSub { size 8{α} } } {}$ x rays created when an electron falls into an $n=1n=1 size 12{n=1} {}$ shell vacancy from the $n=3n=3 size 12{n=3} {}$ shell
$K β K β size 12{K rSub { size 8{β} } } {}$ x rays created when an electron falls into an $n=2n=2 size 12{n=2} {}$ shell vacancy from the $n=3n=3 size 12{n=3} {}$ shell
$kcal kcal size 12{"kcal"} {}$ kilocalorie
$KE KE size 12{"KE"} {}$ translational kinetic energy
$KE + PE KE + PE size 12{"KE"+" PE"} {}$ mechanical energy
$KE e KE e size 12{"KE" rSub { size 8{e} } } {}$ kinetic energy of an ejected electron
$KE rel KE rel size 12{"KE" rSub { size 8{"rel"} } } {}$ relativistic kinetic energy
$KE rot KE rot size 12{"KE" rSub { size 8{"rot"} } } {}$ rotational kinetic energy
$KE ¯ KE ¯ size 12{ {overline {"KE"}} } {}$ thermal energy
$kg kg size 12{"kg"} {}$ kilogram (a fundamental SI unit of mass)
$L L size 12{L} {}$ angular momentum
$L L size 12{L} {}$ liter
$L L size 12{L} {}$ magnitude of angular momentum
$L L size 12{L} {}$ self-inductance
$ℓ ℓ size 12{ℓ} {}$ angular momentum quantum number
$L α L α size 12{L rSub { size 8{α} } } {}$ x rays created when an electron falls into an $n=2n=2 size 12{n=2} {}$ shell from the $n=3n=3 size 12{n=3} {}$ shell
$L e L e size 12{L rSub { size 8{e} } } {}$ electron total family number
$L μ L μ size 12{L rSub { size 8{μ} } } {}$ muon family total number
$L τ L τ size 12{L rSub { size 8{τ} } } {}$ tau family total number
$L f L f size 12{L rSub { size 8{f} } } {}$ heat of fusion
$L f and L v L f and L v size 12{L rSub { size 8{f} } " and" L rSub { size 8{v} } } {}$ latent heat coefficients
$L orb L orb size 12{L rSub { size 8{"orb"} } } {}$ orbital angular momentum
$L s L s size 12{L rSub { size 8{s} } } {}$ heat of sublimation
$L v L v size 12{L rSub { size 8{v} } } {}$ heat of vaporization
$L z L z size 12{L rSub { size 8{z} } } {}$ z - component of the angular momentum
$M M size 12{M} {}$ angular magnification
$M M size 12{M} {}$ mutual inductance
$m m size 12{m} {}$ indicates metastable state
$m m size 12{m} {}$ magnification
$m m size 12{m} {}$ mass
$m m size 12{m} {}$ mass of an object as measured by a person at rest relative to the object
$m m size 12{m} {}$ meter (a fundamental SI unit of length)
$m m size 12{m} {}$ order of interference
$m m size 12{m} {}$ overall magnification (product of the individual magnifications)
$m A X m A X size 12{m left ("" lSup { size 8{A} } X right )} {}$ atomic mass of a nuclide
$MA MA size 12{"MA"} {}$ mechanical advantage
$m e m e size 12{m rSub { size 8{e} } } {}$ magnification of the eyepiece
$m e m e size 12{m rSub { size 8{e} } } {}$ mass of the electron
$m ℓ m ℓ size 12{m rSub { size 8{ℓ} } } {}$ angular momentum projection quantum number
$m n m n size 12{m rSub { size 8{n} } } {}$ mass of a neutron
$m o m o size 12{m rSub { size 8{o} } } {}$ magnification of the objective lens
$mol mol size 12{"mol"} {}$ mole
$m p m p size 12{m rSub { size 8{p} } } {}$ mass of a proton
$m s m s size 12{m rSub { size 8{s} } } {}$ spin projection quantum number
$N N size 12{N} {}$ magnitude of the normal force
$N N size 12{N} {}$ newton
$N N size 12{N} {}$ normal force
$N N size 12{N} {}$ number of neutrons
$n n size 12{n} {}$ index of refraction
$n n size 12{n} {}$ number of free charges per unit volume
$N A N A size 12{N rSub { size 8{A} } } {}$ Avogadro's number
$N r N r size 12{N rSub { size 8{r} } } {}$ Reynolds number
$N ⋅ m N ⋅ m size 12{N cdot m} {}$ newton-meter (work-energy unit)
$N ⋅ m N ⋅ m size 12{N cdot m} {}$ newtons times meters (SI unit of torque)
$OE OE size 12{"OE"} {}$ other energy
$P P size 12{P} {}$ power
$P P size 12{P} {}$ power of a lens
$P P size 12{P} {}$ pressure
$p p size 12{p} {}$ momentum
$p p size 12{p} {}$ momentum magnitude
$p p size 12{p} {}$ relativistic momentum
$p tot p tot size 12{p rSub { size 8{"tot"} } } {}$ total momentum
$p tot ' p tot ' size 12{ { {p}} sup { ' } rSub { size 8{`"tot"} } } {}$ total momentum some time later
$P abs P abs size 12{P rSub { size 8{"abs"} } } {}$ absolute pressure
$P atm P atm size 12{P rSub { size 8{"atm"} } } {}$ atmospheric pressure
$P atm P atm size 12{P rSub { size 8{"atm"} } } {}$ standard atmospheric pressure
$PE PE size 12{"PE"} {}$ potential energy
$PE el PE el size 12{"PE" rSub { size 8{"el"} } } {}$ elastic potential energy
$PE elec PE elec size 12{"PE" rSub { size 8{"elec"} } } {}$ electric potential energy
$PE s PE s size 12{"PE" rSub { size 8{s} } } {}$ potential energy of a spring
$P g P g size 12{P rSub { size 8{g} } } {}$ gauge pressure
$P in P in size 12{P rSub { size 8{"in"} } } {}$ power consumption or input
$P out P out size 12{P rSub { size 8{"out"} } } {}$ useful power output going into useful work or a desired, form of energy
$Q Q size 12{Q} {}$ latent heat
$Q Q size 12{Q} {}$ net heat transferred into a system
$Q Q size 12{Q} {}$ flow rate—volume per unit time flowing past a point
$+ Q + Q size 12{+Q} {}$ positive charge
$− Q − Q size 12{ - Q} {}$ negative charge
$q q size 12{q} {}$ electron charge
$q p q p size 12{q rSub { size 8{p} } } {}$ charge of a proton
$q q size 12{q} {}$ test charge
$QF QF size 12{"QF"} {}$ quality factor
$R R size 12{R} {}$ activity, the rate of decay
$R R size 12{R} {}$ radius of curvature of a spherical mirror
$R R size 12{R} {}$ red quark color
$R ¯ R ¯ size 12{ {overline {R}} } {}$ antired (cyan) quark color
$R R size 12{R} {}$ resistance
$R R size 12{R} {}$ resultant or total displacement
$R R size 12{R} {}$ Rydberg constant
$R R size 12{R} {}$ universal gas constant
$r r size 12{r} {}$ distance from pivot point to the point where a force is applied
$r r size 12{r} {}$ internal resistance
$r ⊥ r ⊥ size 12{r rSub { size 8{ ortho } } } {}$ perpendicular lever arm
$r r size 12{r} {}$ radius of a nucleus
$r r size 12{r} {}$ radius of curvature
$r r size 12{r} {}$ resistivity
$r or rad r or rad size 12{"r or rad"} {}$ radiation dose unit
$rem rem size 12{"rem"} {}$ roentgen equivalent man
$rad rad size 12{"rad"} {}$ radian
$RBE RBE size 12{"RBE"} {}$ relative biological effectiveness
$RC RC size 12{ ital "RC"} {}$ resistor and capacitor circuit
$rms rms size 12{"rms"} {}$ root mean square
$r n r n size 12{r rSub { size 8{n} } } {}$ radius of the nth H-atom orbit
$R p R p size 12{R rSub { size 8{p} } } {}$ total resistance of a parallel connection
$R s R s size 12{R rSub { size 8{s} } } {}$ total resistance of a series connection
$R s R s size 12{R rSub { size 8{s} } } {}$ Schwarzschild radius
$S S size 12{S} {}$ entropy
$S S size 12{S} {}$ intrinsic spin (intrinsic angular momentum)
$S S size 12{S} {}$ magnitude of the intrinsic (internal) spin angular momentum
$S S size 12{S} {}$ shear modulus
$S S size 12{S} {}$ strangeness quantum number
$s s size 12{s} {}$ quark flavor strange
$s s size 12{s} {}$ second (fundamental SI unit of time)
$s s size 12{s} {}$ spin quantum number
$s s size 12{s} {}$ total displacement
$sec θ sec θ size 12{"sec"θ} {}$ secant
$sin θ sin θ size 12{"sin"θ} {}$ sine
$s z s z size 12{s rSub { size 8{z} } } {}$ z-component of spin angular momentum
$T T size 12{T} {}$ period—time to complete one oscillation
$T T size 12{T} {}$ temperature
$T c T c size 12{T rSub { size 8{c} } } {}$ critical temperature—temperature below which a material becomes a superconductor
$T T size 12{T} {}$ tension
$T T size 12{T} {}$ tesla (magnetic field strength B)
$t t size 12{t} {}$ quark flavor top or truth
$t t size 12{t} {}$ time
$t 1 / 2 t 1 / 2 size 12{t rSub { size 8{ {1} slash {2} } } } {}$ half-life—the time in which half of the original nuclei decay
$tan θ tan θ size 12{"tan"θ} {}$ tangent
$U U size 12{U} {}$ internal energy
$u u size 12{u} {}$ quark flavor up
$u u size 12{u} {}$ unified atomic mass unit
$u u size 12{u} {}$ velocity of an object relative to an observer
$u ' u ' size 12{ { {u}} sup { ' }} {}$ velocity relative to another observer
$V V size 12{V} {}$ electric potential
$V V size 12{V} {}$ terminal voltage
$V V size 12{V} {}$ volt (unit)
$V V size 12{V} {}$ volume
$v v size 12{v} {}$ relative velocity between two observers
$v v size 12{v} {}$ speed of light in a material
$v v size 12{v} {}$ velocity
$v ¯ v ¯ size 12{ {overline {v}} } {}$ average fluid velocity
$V B − V A V B − V A size 12{V rSub { size 8{B} } - V rSub { size 8{A} } } {}$ change in potential
$v d v d size 12{v rSub { size 8{d} } } {}$ drift velocity
$V p V p size 12{V rSub { size 8{p} } } {}$ transformer input voltage
$V rms V rms size 12{V rSub { size 8{"rms"} } } {}$ rms voltage
$V s V s size 12{V rSub { size 8{s} } } {}$ transformer output voltage
$v tot v tot size 12{v rSub { size 8{"tot"} } } {}$ total velocity
$v w v w size 12{v rSub { size 8{w} } } {}$ propagation speed of sound or other wave
$v w v w size 12{v rSub { size 8{w} } } {}$ wave velocity
$W W size 12{W} {}$ work
$W W size 12{W} {}$ net work done by a system
$W W size 12{W} {}$ watt
$w w size 12{w} {}$ weight
$w fl w fl size 12{w rSub { size 8{"fl"} } } {}$ weight of the fluid displaced by an object
$W c W c size 12{W rSub { size 8{c} } } {}$ total work done by all conservative forces
$W nc W nc size 12{W rSub { size 8{"nc"} } } {}$ total work done by all nonconservative forces
$W out W out size 12{W rSub { size 8{"out"} } } {}$ useful work output
$X X size 12{X} {}$ amplitude
$X X size 12{X} {}$ symbol for an element
$Z A X N Z A X N size 12{"" lSub { size 8{Z} } lSup { size 8{A} } X rSub { size 8{N} } } {}$ notation for a particular nuclide
$x x size 12{x} {}$ deformation or displacement from equilibrium
$x x size 12{x} {}$ displacement of a spring from its undeformed position
$x x size 12{x} {}$ horizontal axis
$X C X C size 12{X rSub { size 8{C} } } {}$ capacitive reactance
$X L X L size 12{X rSub { size 8{L} } } {}$ inductive reactance
$x rms x rms size 12{x rSub { size 8{"rms"} } } {}$ root mean square diffusion distance
$y y size 12{y} {}$ vertical axis
$Y Y size 12{Y} {}$ elastic modulus or Young's modulus
$Z Z size 12{Z} {}$ atomic number (number of protons in a nucleus)
$Z Z size 12{Z} {}$ impedance
Table D1