Question

The density of water 1.0 g $c{m}^{-}3$. The density of iron is 7.8 g $c{m}^{-}3$. The density of mercury is of 13.6 g $c{m}^{-}3$. Answer the following :

(a) Will a piece of an iron float or sink in water?

(b) Will a piece of an iron float or sink in mercury?

Answer 1

The density of water 1.0 g $c{m}^{-3}$
(a) Density of piece of iron = $7.8\times$ ${10}^{-3}$ g $c{m}^{-3}$ < 1 g $c{m}^{-3}$
∴ The density of a piece of iron is LESS than the density of water.
Hence, a piece of iron will FLOAT in water.

(b) Density of piece of iron = $7.8\times$ ${10}^{-3}$
Density of mercury is $13.6\times$ ${10}^{-3}$ g $c{m}^{-3}$
Since $7.8\times$ ${10}^{-3}$ < $13.6\times$ ${10}^{-3}$

∴ Density of piece of iron is LESS than the density of mercury.
∴ The piece of iron will FLOAT in mercury.