Question

A block of metal floats in a liquid with ${\frac{3}{7}}^{th}$ of volume inside the surface of liquid the density of wood is:

• A. $3.378g/c{m}^3$
• B. $0.4g/c{m}^3$
• C. $0.428g/c{m}^2$
• D. $0.52g/c{m}^3$

Answer 1

The correct option is C $0.428g/c{m}^2$

Volume of block = $\frac{3}{7}V$

By the principle of floatation

Weight of the block = Weight of the water displace by immersed part of the block

$V\times {\delta }_w\times g=\left(\frac{3}{7}V\right)\times 1\times g$

${\delta }_w=\frac{3}{7}gc{m}^{-3}$