m = 480 cm3 x 2.7 g/cm3
m = 1296 g
The mass of the aluminium block is 1 296 g or 1.296 kg.
The units of density
For small volumes density is measured in g/cm3.
For larger volumes density is measured in kg/m3.
Aluminium has a density of 2.7 g/cm3 = 2,700 kg/m3.
Water has a density of 1.0 g/cm3, or 1000 kg/m3.
Knowing the density of a material enables an engineer or architect to calculate the mass of a building or structure from its volume.
This in turn enables them to determine the correct depth of foundation to make the building safe.
An Olympic size swimming pool measures 50 m long, 25 m wide and has an average depth 2 m. What is the mass of water in the pool if the density of water is 1000 kg/m3?
The swimming pool is a regular shape and so the volume of water is calculated using the equation:
Volume = length x breadth x height
Volume = 50 m x 25 m x 2 m = 2500 m3
v = 2500 m3
m = 2500 m3 x 1000 kg/m3
m = 2,500,000 kg
The mass of water in the swimming pool is 2,500,000 kg or 2500 tonnes.