The Bulk Density of a Brick Water Displacement Method

Density Density, ρ = Mass Volume The Greek symbol used for density is ρ which is pronounced “ro”.

Density Mass is relatively easy as the brick can be weighed in air to give its mass (m 1 gm) Mass in air, m 1 = gm

Density Volume is more difficult as the brick is quite a complicated shape, it is not very evenly shaped and it has quite a rough surface.

Density However, the Volume can be calculated by weighing the brick in air (m 1 gm) and then weighing it fully immersed in water (m 2 gm) The mass of water displaced by the brick = Mass in air (m 1 gm) – Mass in water (m 2 gm) Mass in water m 2 = gm

Density The density of water, ρ w, can be assumed to be 1 gm/cm 3 Hence, the volume of the brick is numerically the same as the mass of water displaced

Density The density can now be calculated Density, ρ = m 1 x ρ w ( m 1 – m 2)

Density Let us put the numbers in for our brick Density, ρ = m 1 x ρ w ( m 1 – m 2) Density, ρ = x 1 g/cm – = 1.93 g/cm 3 As 1 g/cm 3 is the same as 1000 kg/m 3, the density can also be stated as 1930 kg/m 3 which is nearly 2 Tonnes per m 3