The relative density of mercury is 13.6. State it's density in (i) C.G.S. unit (ii) S.I. unit.

The density of iron is 7.8 x 10³ kg m^-3. What is it's relative density ?

Calculate the mass of a body whose volume is 2 m³ and relative density is 0.52.

Calculate the mass of air in a room of dimensions 4.5 m x 3.5 m x 2.5 m if the density of air at N.T.P. is 1.3 kg m^-3