Physics Symbols and Notations
Space And Time
| Symbol | Description |
|---|---|
| r, r | Position, separation, radius, radius of curvature |
| s, s | Displacement, distance |
| θ, φ | Angle, angular displacement, angular separation, rotation angle |
| x, y, z | Cartesian coordinates |
| î, ĵ, k̂ | Cartesian unit vectors |
| r, θ, φ | Spherical coordinates |
| r̂, θ̂, φ̂ | Spherical unit vectors |
| ρ, φ, z | Cylindrical coordinates |
| ρ̂, φ̂, ẑ | Cylindrical unit vectors |
| n̂ | Normal unit vector |
| t̂ | Tangential unit vector |
| h | Height, depth |
| ℓ, L | Length |
| d | Distance, separation, thickness |
| t | Thickness |
| D | Diameter |
| C | Circumference |
| A, A | Area, cross-sectional area, projected area, surface area |
| V | Volume |
| t | Time, duration |
| T | Period, periodic time |
| τ | Time constant |
| f | Frequency |
| ω | Angular frequency |
Mechanics
| Symbol | Description |
|---|---|
| v, v | Velocity, speed |
| a, a | Acceleration |
| ac, ac | Centripetal acceleration, centrifugal acceleration |
| g, g | Gravitational field, acceleration due to gravity |
| m | Mass |
| F, F | Force |
| Fg, W, W | Force of gravity, weight |
| Fn, N, N | Normal force, normal |
| Ff, fs, fk | Force of friction (static, kinetic) |
| μs, μk | Coefficient of friction (static, kinetic) |
| p, p | Momentum |
| J, J | Impulse |
| W | Work |
| E | Energy, total energy |
| K, Kt, Kr | Kinetic energy (translational, rotational) |
| U, Ug, Us | Potential energy (gravitational, spring) |
| Vg | Gravitational potential |
| η | Efficiency |
| P | Power |
| ω, ω | Rotational velocity, rotational speed |
| α, α | Rotational acceleration |
| τ, τ | Torque |
| I | Moment of inertia |
| L, L | Angular momentum |
| H, H | Angular impulse |
| k | Spring constant |
| P | Pressure |
| σ | Normal stress |
| τ | Shear stress |
| ρ | Density, volume mass density |
| σ | Area mass density, superficial mass density |
| λ | Linear mass density |
| FB, B, B | Buoyancy, buoyant force |
| qm | Mass flow rate |
| qV | Volume flow rate |
| FD, R, R | Drag, aerodynamic drag, air resistance |
| C, CD | Drag coefficient, coefficient of drag |
| η | Viscosity, dynamic viscosity |
| ν | Kinematic viscosity |
| Ma | Mach number |
| Re | Reynolds number |
| Fr | Froude number |
| E | Young's modulus, modulus of elasticity |
| G | Shear modulus, modulus of rigidity |
| K | Bulk modulus, modulus of compression |
| ε | Linear strain |
| γ | Shear strain |
| θ | Volume strain |
| γ | Surface tension |
Thermal Physics
| Symbol | Description |
|---|---|
| T | Temperature |
| α | Linear expansivity, coefficient of linear thermal expansion |
| β | Volume expansivity, coefficient of volume thermal expansion |
| Q | Heat |
| c | Specific heat, specific heat capacity |
| L | Latent heat, specific latent heat |
| n | Amount of substance |
| N | Number of particles |
| P | Heat flow rate |
| k | Thermal conductivity |
| ε | Emissivity |
| U | Internal energy |
| S | Entropy |
| w | Ways, number of identical microstates |
| COP | Coefficient of performance |
Waves and Optics
| Symbol | Description |
|---|---|
| λ | Wavelength |
| v, c | Wave speed |
| I | Intensity |
| L | Level |
| n | Index of refraction, absolute index of refraction |
| f | Focal length |
| M | Magnification |
Electricity and Magnetism
| Symbol | Description |
|---|---|
| q, Q | Charge, electric charge |
| ρ | Charge density, volume charge density |
| σ | Area charge density, superficial charge density |
| λ | Linear charge density |
| FE | Electric force, electrostatic force |
| E | Electric field |
| ΦE | Electric flux |
| U, UE | Potential energy, electric potential energy |
| V, VE | Voltage, potential, electric potential |
| ℰ | Electromotive force, emf |
| C | Capacitance |
| κ | Dielectric constant |
| I | Current, electric current |
| R, r | Resistance, electrical resistance, internal resistance |
| ρ | Resistivity |
| G | Conductance |
| σ | Conductivity |
| FB | Magnetic force |
| B | Magnetic field |
| ΦB | Magnetic flux |
| N | Number of turns |
| n | Turns per unit length, turns density |
| η | Energy density |
| S | Poynting vector, intensity |
Modern Physics
| Symbol | Description |
|---|---|
| γ | Lorentz factor, lorentz gamma |
| φ | Work function |
| ψ(r,t), ψ(r)φ(t) | Wave function |
| T½ | Half-life |
| D | Dose, absorbed dose |
| H | Equivalent dose |
| E | Effective dose |
| wR | Radiation weighting factor |
| wT | Tissue weighting factor |
Mathematical Symbols and Notation
| Symbol | Description |
|---|---|
| + | Plus, add, sum, positive |
| − | Minus, subtract, difference, negative |
| ± | Uncertainty, error, plus-minus |
| · | Multiply, dot, dot product, scalar product |
| × | Multiply, cross, cross product, vector product |
| ÷, / | Divide |
| x² | Square |
| x³ | Cube |
| √ | Square root, root, radical |
| ∛ | Cube root |
| 1/x, x⁻¹ | Invert, reciprocal |
| = | Equal to, equality |
| ≈ | Approximately equal to |
| ∝ | Proportional to |
| ≠ | Not equal to, inequality |
| ~ | On the order of |
| < | Less than |
| > | Greater than |
| ≤ | Less than or equal to |
| ≥ | Greater than or equal to |
| ≪ | Much less than |
| ≫ | Much greater than |
| ⇒ | Logical implication |
| ⇔ | Logical equivalence |
| → | Approaches |
| … | And so on |
| ∴ | Therefore |
| f(x) | Function |
| sin | Sine |
| cos | Cosine |
| tan | Tangent |
| sinh | Hyperbolic sine |
| cosh | Hyperbolic cosine |
| tanh | Hyperbolic tangent |
| x̂ | Unit vector, x hat |
| ∥ | Parallel |
| ⟂ | Perpendicular |
| x̅ | Mean, average, antiparticle |
| x̃ | Median, supersymetric particle |
| ⟨⟩ | Time average, ensemble average, bracket |
| p(x) | Probability distribution, probability density function |
| ∆ | Increment, change, delta |
| d | Differential, d |
| ∂ | Partial differential, d partial, del |
| ẋ | Time rate of change, first derivative with respect to time |
| ẍ | Second derivative with respect to time |
| x⃛ | Third derivative with respect to time |
| ∇ | Gradient, grad, del, nabla |
| ∇ · | Divergence, del dot |
| ∇ × | Curl, del cross |
| ∇² | Laplacian, del squared |
| ∑ | Summation, sigma |
| ∫ | Integral |
| ∬ | Double integral |
| ∭ | Triple integral |
| ∮ | Contour integral |
| ∯ | Surface integral |
| ∰ | Volume integral |
| ∞ | Infinity |
| ℵ₀ | Transfinite number, aleph null |
Greek Alphabet (with Variants)
| Letter | Name | Letter | Name |
|---|---|---|---|
| Α, α | Alpha | Ν, ν | Nu |
| Β, β, ϐ | Beta | Ξ, ξ | Xi |
| Γ, γ | Gamma | Ο, ο | Omicron |
| Δ, ∆, δ | Delta | Π, ∏, π, ϖ | Pi |
| Ε, ε, ϵ | Epsilon | Ρ, ρ, ϱ | Rho |
| Ζ, ζ | Zeta | Σ, ∑, σ, ς | Sigma |
| Η, η | Eta | Τ, τ | Tau |
| Θ, ϴ, θ, ϑ | Theta | Υ, υ | Upsilon |
| Ι, ι | Iota | Φ, φ, ϕ | Phi |
| Κ, κ, ϰ | Kappa | Χ, χ | Chi |
| Λ, λ | Lambda | Ψ, ψ | Psi |
| Μ, μ, µ | Mu | Ω, Ω, ω | Omega |