(i)Define relative density.Give its mathematical form.

(ii)The mass of an iron cube having an edge length 1.5 cm is 50 g. Find its density.

(iii)The volume of a 250 g sealed tin is 400 cubic cm. Find the density of the tin in g ${{cc}^{-1}}$. State, if the object would sink or ‘ float in water.

(i) The relative density of a substance is the ratio of its density to that of water.

Relative velocity of substance = Density of substance / Density of Water

In other words, Relative density of substance = Mass of substance / Volume of the substance x Volume of water / Mass of water

(ii)Given that , mass of the cube = 50 g

Side of the cube = 1.5 cm

Volume of the cube = ${{1.5}^{3}}$ ${{cm}^{3}}$

Density = Mass / Volume = 50/ 3.375 = 14.81 ${{cm}^{-3}}$

(iii) Given that , mass ,m =250g

Volume,V = 400cc

Density = Mass / Volume = 250/400 = 0.625 g ${{cc}^{-1}}$

As we know that, density of water = 1 g ${{cc}^{-1}}$. So, density of tin is less than that of water and hence tin will float.