Base quantities::Physical quantity
::concepts
Mathrm::physical Quantity::mathbf Width::scope Surface::property Symbol::density Current::units
Base quantities
{{#invoke:main|main}}
Base quantities are those quantities on the basis of which other quantities can be expressed. The seven base quantities of the International System of Quantities (ISQ) and their corresponding SI units and dimensions are listed in the following table. Other conventions may have a different number of base units (e.g. the CGS and MKS systems of units).
Quantity name/s | (Common) Quantity symbol/s | SI unit name | SI unit symbol | Dimension symbol |
---|---|---|---|---|
Length, width, height, depth | a, b, c, d, h, l, r, s, w, x, y, z | metre | m | L |
Time | t, τ | second | s | T |
Mass | m | kilogram | kg | M |
Temperature | T, θ | kelvin | K | Θ |
Amount of substance | n | mole | mol | N |
Electric current | i, I | ampere | A | I |
Luminous intensity | I_{v} | candela | cd | J |
Plane angle | α, β, γ, θ, φ, χ | radian | rad | 1 |
Solid angle | ω, Ω | steradian | sr | 1 |
The last two angular units, plane angle and solid angle, are subsidiary units used in the SI, but are treated as dimensionless. The subsidiary units are used for convenience to differentiate between a truly dimensionless quantity (pure number) and an angle, which are different measurements.
Physical quantity sections
Intro Symbols, nomenclature Units and dimensions Base quantities General derived quantities See also References Sources
Base quantities | |
PREVIOUS: Units and dimensions | NEXT: General derived quantities |
<< | >> |