List of common physics notations
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This is a list of common physical constants and variables, and their notations. Note that bold text indicates that the quantity is a vector.
Latin characters
[edit ]| Symbol | Meaning | SI unit of measure |
|---|---|---|
| {\displaystyle \mathbf {A} } | magnetic vector potential | tesla meter (T⋅m) |
| {\displaystyle A} | area | square meter (m2) |
| amplitude | meter | |
| atomic mass number | unitless | |
| {\displaystyle \mathbf {a} } | acceleration | meter per second squared (m/s2) |
| {\displaystyle \mathbf {B} } | magnetic flux density also called the magnetic field density or magnetic induction |
tesla (T), or equivalently, weber per square meter (Wb/m2) |
| {\displaystyle C} | capacitance | farad (F) |
| heat capacity | joule per kelvin (J⋅K−1) | |
| constant of integration | varied depending on context | |
| {\displaystyle c} | speed of light (in vacuum) | 299,792,458 meters per second (m/s) |
| speed of sound | meter per second (m/s) | |
| specific heat capacity | joule per kilogram per kelvin (J⋅kg−1⋅K−1) | |
| viscous damping coefficient | kilogram per second (kg/s) | |
| {\displaystyle \mathbf {D} } | electric displacement field also called the electric flux density |
coulomb per square meter (C/m2) |
| {\displaystyle D} | density | kilogram per cubic meter (kg/m3) |
| diameter | meter (m) | |
| {\displaystyle d} | distance | meter (m) |
| direction | unitless | |
| impact parameter | meter (m) | |
| differential (e.g. {\displaystyle dx}) | varied depending on context | |
| {\displaystyle d\mathbf {A} } | differential vector element of surface area A, with infinitesimally small magnitude and direction normal to surface S | square meter (m2) |
| {\displaystyle dV} | differential element of volume V enclosed by surface S | cubic meter (m3) |
| {\displaystyle \mathbf {E} } | electric field | newton per coulomb (N⋅C−1), or equivalently, volt per meter (V⋅m−1) |
| {\displaystyle E} | energy | joule (J) |
| Young's modulus | pascal (Pa) or newton per square meter (N/m2) | |
| {\displaystyle e} | eccentricity | unitless |
| Euler's number (2.71828, base of the natural logarithm) | unitless | |
| electron | unitless | |
| elementary charge | coulomb (C) | |
| {\displaystyle \mathbf {F} } | force | newton (N) |
| {\displaystyle F} | Faraday constant | coulombs per mole (C⋅mol−1) |
| {\displaystyle f} | frequency | hertz (Hz) |
| function | ||
| friction | newton (N) | |
| {\displaystyle G} | electrical conductance | siemens (S) |
| universal gravitational constant | newton meter squared per kilogram squared (N⋅m2/kg2) | |
| shear modulus | pascal (Pa) or newton per square meter (N/m2) | |
| gluon field strength tensor | inverse length squared (1/m2) | |
| {\displaystyle \mathbf {g} } | acceleration due to gravity | meters per second squared (m/s2), or equivalently, newtons per kilogram (N/kg) |
| {\displaystyle \mathbf {H} } | magnetic field strength | ampere per meter (A/m) |
| {\displaystyle H} | Hamiltonian | joule (J) |
| enthalpy | joule (J) | |
| thermal current | watt (W) | |
| {\displaystyle h} | height | meter (m) |
| Planck constant | joule second (J⋅s) | |
| {\displaystyle \hbar } | reduced Planck constant | joule second (J⋅s) |
| {\displaystyle I} | action | joule second (J⋅s) |
| intensity | watt per square meter (W/m2) | |
| sound intensity | watt per square meter (W/m2) | |
| electric current | ampere (A) | |
| moment of inertia | kilogram meter squared (kg⋅m2) | |
| {\displaystyle i} | intensity | watt per square meter (W/m2) |
| imaginary unit | unitless | |
| electric current | ampere (A) | |
| {\displaystyle \mathbf {\hat {\imath }} } | Cartesian x-axis basis unit vector | unitless |
| {\displaystyle \mathbf {J} } | current density | ampere per square meter (A/m2) |
| impulse | kilogram meter per second (kg⋅m/s) | |
| {\displaystyle \mathbf {j} } | jerk | meter per second cubed (m/s3) |
| {\displaystyle j} | imaginary unit (electrical) | unitless |
| {\displaystyle \mathbf {\hat {\jmath }} } | Cartesian y-axis basis unit vector | unitless |
| {\displaystyle K} | kinetic energy | joule (J) |
| {\displaystyle \mathbf {k} } | wave vector | radian per meter (m−1) |
| {\displaystyle k} | Boltzmann constant | joule per kelvin (J/K) |
| wavenumber | radian per meter (m−1) | |
| stiffness | newton per meter (N⋅m−1) | |
| {\displaystyle \mathbf {\hat {k}} } | Cartesian z-axis basis unit vector | unitless |
| {\displaystyle \mathbf {L} } | angular momentum | newton meter second (N⋅m⋅s or kg⋅m2⋅s−1) |
| {\displaystyle L} | inductance | henry (H) |
| luminosity | watt (W) | |
| Lagrangian | joule (J) | |
| {\displaystyle {\mathcal {L}}} | Lagrangian density | joule per cubic meter (J/m3) |
| {\displaystyle l} | length | meter (m) |
| l | azimuthal quantum number | unitless |
| {\displaystyle \mathbf {M} } | magnetization | ampere per meter (A/m) |
| {\displaystyle M} | moment of force often simply called moment or torque |
newton meter (N⋅m) |
| {\displaystyle m} | mass | kilogram (kg) |
| {\displaystyle \mathbf {N} } | normal vector | unit varies depending on context |
| {\displaystyle N} | atomic number | unitless |
| {\displaystyle n} | refractive index | unitless |
| principal quantum number | unitless | |
| amount of substance | mole | |
| {\displaystyle P} | power | watt (W) |
| active power (real power) | watt (W) | |
| probability | unitless | |
| {\displaystyle \mathbf {p} } | momentum | kilogram meter per second (kg⋅m/s) |
| {\displaystyle p} | pressure | pascal (Pa) |
| {\displaystyle Q} | electric charge | coulomb (C) |
| heat | joule (J) | |
| Reactive Power | volt-ampere reactive (var) | |
| {\displaystyle q} | electric charge | coulomb (C) |
| {\displaystyle R} | electrical resistance | ohm (Ω) |
| Ricci tensor | reciprocal square meter (m−2) | |
| radiancy | meter per second | |
| gas constant | joule per mole per kelvin (J⋅mol−1⋅K−1) | |
| {\displaystyle \mathbf {r} } | radius vector (position) | meter (m) |
| {\displaystyle r} | radius or distance | meter (m) |
| {\displaystyle S} | surface area | square meter (m2) |
| entropy | joule per kelvin (J/K) | |
| action | joule second (J⋅s) | |
| apparent power (complex power) | Volt-Ampere (VA) | |
| {\displaystyle \mathbf {s} } | displacement | meter (m) |
| {\displaystyle s} | arc length | meter (m) |
| distance | meter (m) | |
| {\displaystyle T} | period | second (s) |
| temperature | kelvin (K) or Celsius (C) | |
| kinetic energy | joule (J) | |
| {\displaystyle t} | time | second (s) |
| {\displaystyle \mathbf {U} } | four-velocity | meter per second (m/s) |
| {\displaystyle U} | potential energy | joule (J) |
| internal energy | joule (J) | |
| {\displaystyle u} | relativistic mass | kilogram (kg) |
| energy density | joule per cubic meter (J/m3) | |
| specific energy | joule per kilogram (J/kg) | |
| {\displaystyle V} | voltage also called electric potential difference |
volt (V) |
| volume | cubic meter (m3) | |
| shear force | ||
| {\displaystyle \mathbf {v} } | velocity | meter per second (m/s) |
| {\displaystyle W} | weight | newton (N) |
| mechanical work | joule (J) | |
| {\displaystyle w} | width | meter (m) |
| {\displaystyle X} | electrical reactance | ohm (Ω) |
| {\displaystyle \mathbf {x} } | position vector | meter (m) |
| displacement | meter (m) | |
| {\displaystyle x} | a generic unknown | varied depending on context |
| {\displaystyle Y} | admittance | siemens (S) |
| {\displaystyle Z} | compressibility factor | unitless |
| electrical impedance | ohm (Ω) | |
| {\displaystyle Z_{0}} | impedance of free space | ohm (Ω) |
Greek characters
[edit ]| Symbol | Name | Meaning | SI unit of measure |
|---|---|---|---|
| {\displaystyle \alpha } | alpha | alpha particle | |
| angular acceleration | radian per second squared (rad/s2) | ||
| fine-structure constant | unitless | ||
| {\displaystyle \beta } | beta | velocity in terms of the speed of light c | unitless |
| beta particle | |||
| {\displaystyle \gamma } | gamma | Lorentz factor | unitless |
| photon | |||
| gamma ray | |||
| shear strain | radian | ||
| heat capacity ratio | unitless | ||
| surface tension | newton per meter (N/m) | ||
| {\displaystyle \Delta } | delta | change in a variable (e.g. {\displaystyle \Delta x}) | unitless |
| Laplace operator | per square meter (m−2) | ||
| {\displaystyle \delta } | displacement (usually small) | meter (m) | |
| Dirac delta function | |||
| Kronecker delta (e.g {\displaystyle \delta _{ij}}) | |||
| {\displaystyle \epsilon } | epsilon | permittivity | farad per meter (F/m) |
| strain | unitless | ||
| {\displaystyle \varepsilon _{0}} | epsilon nought | Vacuum permittivity | farad per meter (F/m) |
| {\displaystyle \zeta } | zeta | damping ratio | unitless |
| {\displaystyle \eta } | eta | angular jerk | radian per second cubed (rad⋅s−3) |
| energy efficiency | unitless | ||
| (dynamic) viscosity (also {\displaystyle \mu }) | pascal second (Pa⋅s) | ||
| {\displaystyle \theta } | theta | angular displacement | radian (rad) |
| {\displaystyle \kappa } | kappa | torsion coefficient also called torsion constant |
newton meter per radian (N⋅m/rad) |
| {\displaystyle \Lambda } | lambda | cosmological constant | per second squared (s−2) |
| {\displaystyle \lambda } | wavelength | meter (m) | |
| linear charge density | coulomb per meter (C/m) | ||
| eigenvalue | non-zero vector | ||
| {\displaystyle \mathbf {\mu } } | mu | magnetic moment | ampere square meter (A⋅m2) |
| coefficient of friction | unitless | ||
| (dynamic) viscosity (also {\displaystyle \eta }) | pascal second (Pa⋅s) | ||
| permeability (electromagnetism) | henry per meter (H/m) | ||
| reduced mass | kilogram (kg) | ||
| Standard gravitational parameter | cubic meter per second squared | ||
| {\displaystyle \mathbf {\mu } _{0}} | mu nought | Vacuum permeability or the magnetic constant | henry per meter (H/m) |
| {\displaystyle \nu } | nu | frequency | hertz (Hz) |
| kinematic viscosity | meter squared per second (m2/s) | ||
| neutrino | |||
| {\displaystyle \xi } | xi | electromotive force | volt (V) |
| {\displaystyle \pi } | pi | 3.14159... (irrational number) | unitless |
| {\displaystyle \rho } | rho | mass density usually simply called density |
kilogram per cubic meter (kg/m3) |
| volume charge density | coulomb per cubic meter (C/m3) | ||
| resistivity | ohm meter (Ω⋅m) | ||
| {\displaystyle \Sigma } | sigma | summation operator | |
| {\displaystyle \sigma } | area charge density | coulomb per square meter (C/m2) | |
| electrical conductivity | siemens per meter (S/m) | ||
| normal stress | pascal (Pa) | ||
| scattering cross section | barn (10^-28 m^2) | ||
| surface tension | newton per meter (N/m) | ||
| {\displaystyle \tau } | tau | torque | newton meter (N⋅m) |
| shear stress | pascal (Pa) | ||
| time constant | second (s) | ||
| 6.28318... (2π) | unitless | ||
| {\displaystyle \Phi } | phi | field strength | unit varies depending on context |
| magnetic flux | weber (Wb) | ||
| {\displaystyle \phi } | electric potential | volt (V) | |
| Higgs field work function | |||
| {\displaystyle \Psi } | psi | wave function | m−3/2 |
| {\displaystyle \Omega } | omega | electric resistance | ohm |
| {\displaystyle \omega } | angular frequency | radian per second (rad/s) | |
| angular velocity | radian per second (rad/s) |
Other characters
[edit ]| Symbol | Name | Meaning | SI unit of measure |
|---|---|---|---|
| {\displaystyle \nabla \cdot } | nabla dot | the divergence operator often pronounced "del dot" |
per meter (m−1) |
| {\displaystyle \nabla \times } | nabla cross | the curl operator often pronounced "del cross" |
per meter (m−1) |
| {\displaystyle \nabla } | nabla | delta (differential operator) | |
| {\displaystyle \partial } | "der", "dow", "die", "partial" or simply "d" | partial derivative (e.g. {\displaystyle \partial y/\partial x}) | |
| {\displaystyle \Box } | D'Alembert operator | {\displaystyle \nabla ^{2}-\partial _{t}^{2}} | |
| {\displaystyle \langle ,円,円\rangle } | angle brackets | average sometimes over Maxwell–Boltzmann distribution |
|
| {\displaystyle \langle \ |\ \rangle } | Dirac notation | ||
| {\displaystyle \int } | integral | the inverse of the derivative. | unitless |
See also
[edit ]- List of letters used in mathematics and science
- Glossary of mathematical symbols
- List of mathematical uses of Latin letters
- Greek letters used in mathematics, science, and engineering
- Physical constant
- Physical quantity
- International System of Units
- ISO 31
References
[edit ]- Elert, Glenn. "Special Symbols". The Physics Hypertextbook. Retrieved 4 August 2021.
- NIST (16 August 2023). "SI Units". www.nist.gov. NIST.