In physics, density is represented by the symbol ρ (pronounced ròu). The SI unit is kg/m³, and the commonly used unit is g/cm³. Its mathematical expression is ρ=m/V. In the SI unit system, the main unit of mass is kilogram, and the main unit of volume is cubic meter, so the mass of 1 cubic meter of material is taken as the density of the material. For non-uniform materials, it is called "average density".

Density calculation:

Density: d = m/v

d = density, m = mass, v = volume