Question

What is the relative density of a block of mass 15 kg whose volume is equal to the volume of 6 kg water at $4^{\circ }C$?

• A.
  0.3
• B.
  9
• C.
  2.5
• D.
  1

Answer 1

The correct option is C

2.5
Mass of the block, M = 15 kg

Volume of block = Volume of water of mass 6 kg at $4^{\circ }C$

Volume of block, V =$\frac{\text{Mass of water}}{\text{Density of water}}\Rightarrow V=\frac{6kg}{1000kg/m^3}(\because \text{Density of water.}{\rho }_w={10}^{3}kg/m^3)\text{Density of block}{\rho }_b=\frac{15}{\frac{6}{1000}}=\frac{15000}{6}kg/m^3$

$\text{Relative density of block}=\frac{\text{Density of block}}{\text{Density of water}}=\frac{{\rho }_b}{{\rho }_w}$

Relative density of block $=\frac{\left(\frac{15000}{6}\right)}{1000}=\frac{15}{6}$

$\Rightarrow$ Relative density of block $=2.5$

Hence the correct answer is option (c).