Appendix A: Units

Units Used in Physics (Fundamental units in bold)

Quantity	Common Symbol	Unit	Unit in Terms of Base SI Units
Acceleration	$$\vec{a}$$	m/s^2	m/s^2
Amount of substance	n	mole	mol
Angle	$$\theta, \phi$$	radian (rad)
Angular acceleration	$$\vec{\alpha}$$	rad/s^2	s^-2
Angular frequency	$$\omega$$	rad/s	s^-1
Angular momentum	$$\vec{L}$$	kg • m/s^2	kg • m/s^2
Angular velocity	$$\vec{\omega}$$	rad/s	s^-1
Area	A	m^2	m^2
Atomic number	Z
Capacitance	C	farad (F)	A^2 • s^4/kg • m^2
Charge	q, Q, e	coulomb (C)	A • s
Charge density:
Line	$$\lambda$$	C/m	A• s/m
Surface	$$\sigma$$	C/m^2	A• s/m^2
Volume	$$\rho$$	C/m^3	A• s/m^3
Conductivity	$$\sigma$$	$$\frac{1}{\Omega \cdotp m}$$	A^2 • s^3/kg • m^3
Current	I	ampere	A
Current density	$$\vec{J}$$	A/m^2	A/m^2
Density	$$\rho$$	kg/m^3	kg/m^3
Dielectric constant	$$\kappa$$
Electric dipole moment	$$\vec{p}$$	C• m	A• s • m
Electric field	$$\vec{E}$$	N/C	kg • m/A • s^3
Electric flux	$$\Phi$$	N • m^2/C	kg • m^3/A • s^3
Electromotive force	$$\varepsilon$$	volt (V)	kg • m^2/A • s^3
Energy	E, U, K	joule (J)	kg • m^2/s^2
Entropy	S	J/K	kg • m^2/s^2 • K
Force	$$\vec{F}$$	newton (N)	kg • m/s^2
Frequency	f	hertz (Hz)	s^-1
Heat	Q	joule (J)	kg • m^2/s^2
Inductance	L	henry (H)	kg • m^2/A^2 • s^2
Length:	$\ell$, L	meter	m
Displacement	$$\Delta x, \Delta \vec{r}$$
Distance	d, h
Position	x, y, z, $\vec{r}$
Magnetic dipole moment	$$\vec{\mu}$$	N • J/T	A • m^2
Magnetic field	$$\vec{B}$$	tesla (T) = Wb/m^2	kg/A • s^2
Magnetic flux	$$\Phi_{m}$$	weber (Wb)	kg • m^2/A • s^2
Mass	m, M	kilogram	kg
Molar specific heat	C	J/mol • K	kg • m^2/s^2• mol • K
Moment of inertia	I	kg • m^2	kg • m^2
Momentum	$$\vec{p}$$	kg • m/s	kg • m/s
Period	T	s	s
Permeability of free space	$$\mu_{0}$$	N/A^2 = H/m	kg • m/A^2 • s^2
Permittivity of free space	$$\varepsilon_{0}$$	C^2/N • m^2= F/m	A^2 • s^4/kg • m^3
Potential	V	volt (V) = J/C	kg • m^2/A^2 • s^3
Power	P	watt (W) = J/s	kg • m^2/s^3
Pressure	p	pascal (Pa) = N/m^2	kg/m• s^2
Resistance	R	ohm ($\Omega$) = V/A	kg • m^2/A^2 • s^3
Specific heat	c	J/kg • K	m^2/s^2• K
Speed	v	m/s	m/s
Temperature	T	kelvin	K
Time	t	second	s
Torque	$$\vec{\tau}$$	N • m	kg • m^2/s^2
Velocity	$$\vec{v}$$	m/s	m/s
Volume	V	m^3	m^3
Wavelength	$$\lambda$$	m	m
Work	W	joule (J) = N • m	kg • m^2/s^2

Contributors and Attributions

• Samuel J. Ling (Truman State University), Jeff Sanny (Loyola Marymount University), and Bill Moebs with many contributing authors. This work is licensed by OpenStax University Physics under a Creative Commons Attribution License (by 4.0).