Relative densities of two substance a and b are 2.5 and 0.9 respectively find the densities of a and b also find whether they will sink or float in water density of water is equal 2000 km metre cube

Relative Density of a substance = density of substance /density of water
Relative density of A = Density of A/density of water
Therefore;  2.5 = density of A /1000 kg/m³
Density of A = 2.5 × 10³ kg/m³

Relative density of B = Density of B/density of water
                             0.9 = Density of B / 1000 kg/m³
Density of B = 0.9 × 1000 kg/m³
                     = 900 kg/m³
Therefore; substance A will sink in water as it is denser than water, ehile substance B will float as it is less denser than water.