Question

A block of wood has mass 4kg, what is the density of the wood if the mass of water is 3kg and its volume is half that of the block of the block of wood ?

Answer 1

M1(mass of wood) = 4 kg
M2(mass of water) = 3 kg
V1(volume of wood) = 2 * V2(volume of water )

Density = mass/volume ======= volume = mass/density
Density of water is 1 kg/m3
V2 = M2/density of water
V2 = 3 kg/m3/1kg/m3
V2 = 3 m3

V1(volume of wood) = 2 * V2
V1 = 2 * 3m3
V1 = 6m3

Density of wood = M1 ( mass of wood)/ V1(volume of wood)
Density of wood = 4 kg/ 6m3 = 2/3 kg/m3