Skip to main content
Physics LibreTexts

Appendix A: Units

  • Page ID
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)

    Units Used in Physics (Fundamental units in bold)

    Quantity Common Symbol Unit Unit in Terms of Base SI Units
    Acceleration $$\vec{a}$$ m/s2 m/s2
    Amount of substance n mole mol
    Angle $$\theta, \phi$$ radian (rad)
    Angular acceleration $$\vec{\alpha}$$ rad/s2 s-2
    Angular frequency $$\omega$$ rad/s s-1
    Angular momentum $$\vec{L}$$ kg • m/s2 kg • m/s2
    Angular velocity $$\vec{\omega}$$ rad/s s-1
    Area A m2 m2
    Atomic number Z
    Capacitance C farad (F) A2 • s4/kg • m2
    Charge q, Q, e coulomb (C) A • s
    Charge density:
    Line $$\lambda$$ C/m A• s/m
    Surface $$\sigma$$ C/m2 A• s/m2
    Volume $$\rho$$ C/m3 A• s/m3
    Conductivity $$\sigma$$ $$\frac{1}{\Omega \cdotp m}$$ A2 • s3/kg • m3
    Current I ampere A
    Current density $$\vec{J}$$ A/m2 A/m2
    Density $$\rho$$ kg/m3 kg/m3
    Dielectric constant $$\kappa$$
    Electric dipole moment $$\vec{p}$$ C• m A• s • m
    Electric field $$\vec{E}$$ N/C kg • m/A • s3
    Electric flux $$\Phi$$ N • m2/C kg • m3/A • s3
    Electromotive force $$\varepsilon$$ volt (V) kg • m2/A • s3
    Energy E, U, K joule (J) kg • m2/s2
    Entropy S J/K kg • m2/s2 • K
    Force $$\vec{F}$$ newton (N) kg • m/s2
    Frequency f hertz (Hz) s-1
    Heat Q joule (J) kg • m2/s2
    Inductance L henry (H) kg • m2/A2 • s2
    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 • m2
    Magnetic field $$\vec{B}$$ tesla (T) = Wb/m2 kg/A • s2
    Magnetic flux $$\Phi_{m}$$ weber (Wb) kg • m2/A • s2
    Mass m, M kilogram kg
    Molar specific heat C J/mol • K kg • m2/s2 • mol • K
    Moment of inertia I kg • m2 kg • m2
    Momentum $$\vec{p}$$ kg • m/s kg • m/s
    Period T s s
    Permeability of free space $$\mu_{0}$$ N/A2 = H/m kg • m/A2 • s2
    Permittivity of free space $$\varepsilon_{0}$$ C2/N • m2 = F/m A2 • s4/kg • m3
    Potential V volt (V) = J/C kg • m2/A2 • s3
    Power P watt (W) = J/s kg • m2/s3
    Pressure p pascal (Pa) = N/m2 kg/m • s2
    Resistance R ohm (\(\Omega\)) = V/A kg • m2/A2 • s3
    Specific heat c J/kg • K m2/s2 • K
    Speed v m/s m/s
    Temperature T kelvin K
    Time t second s
    Torque $$\vec{\tau}$$ N • m kg • m2/s2
    Velocity $$\vec{v}$$ m/s m/s
    Volume V m3 m3
    Wavelength $$\lambda$$ m m
    Work W joule (J) = N • m kg • m2/s2

    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).

    Appendix A: Units is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.