Definition:Density (Physics)

Definition
Density is a physical quantity.

The density of a body is its mass per unit volume.

For a homogeneous body it is found by finding its total mass and dividing it by its total volume.

However, if the substance of the body varies throughout, then its density may be a function of position within the body.

The usual symbol used to denote density is $\rho$ (Greek letter rho).

Dimension of Density
The dimension of density is $M L^{-3}$: mass per unit volume.

Units of Density

 * The SI units of density are $\mathrm {kg} \ \mathrm m^{-3}$ (kilograms per cubic metre).


 * The CGS units of density are $\mathrm g \ \mathrm{cm}^{-3}$ or, less formally: $\mathrm g / \mathrm {cc}$ (grams per cubic centimetre).

Thus:
 * $1 \ \mathrm g \ \mathrm {cm}^{-3} = 1000 \ \mathrm {kg} \ \mathrm m^{-3}$

Also see

 * Definition:Dirichlet Density