Question

A wooden cube floating in water supports a mass $0.2kg$ When the mass is removed the cube rises by $2cm.$ The side of the cube is (density of water=${10}^{3}kg/m^3$)

• A. $6cm$
• B. $12cm$
• C. $8cm$
• D. $10cm$

Answer 1

The correct option is D $10cm$

mass of the object $,m=0.2$ kg

density of water $\rho ={10}^{3}kg/m^3$

let. side of $cube=a$

cube rises by $1=2cm$

$\therefore$ (removed mass) $xg=$ increase in buoyant

force

$\begin{array}{cc}0.2\times g& =A.l\cdot {10}^3\cdot g\\ 0.2& =a^2\times \frac{2}{100}\times {10}^3\\ a^2& =\frac{1}{100}\\ a& =\frac{1}{10}m\end{array}$

$ora=10cm$

So the correct option is (D).