This is when:
A piece of aluminium has a mass of 200 kg and a volume of 0.074 m3. Calculate its density in kg/m3, to two significant figures.
The kilogram (kg) is the standard unit for mass. The cubic metre (m3) is the standard unit for volume. However, in many laboratory situations mass will be measured in grams (g) and volume in cubic centimetres (cm3).
A piece of iron has a mass of 100 g and a volume of 12.7 cm3. Calculate its density in g/cm3.
To convert between units:
The density of air at 20 °C is 0.00120 g/cm3. Give its density in kg/m3.
density = 0.00120 × 1,000
= 1.20 kg/m3