Question

An ice cube of size $a=10cm$ is floating in a tank $(base=50cm\times 50cm)$ partially filled with water. The change in gravitational potential energy, when ice completely melts is ________ [Density of ice is $900kg{m}^{-3}$ and $g=10m{s}^{-2}]$.

• A. $-0.0455J$
• B. $-0.016J$
• C. $-0.24J$
• D. $-0.072J$

Answer 1

The correct option is A $-0.0455J$

Relative density of ice is $0.9$ hence $90$% of volume of ice is immersed in water when melts completely level of water does not change.

Therefore change in $CG=${ GG }^{ 1 }=0.5cm$

Change in potential energy

$\Delta V=-mgh$

$={-\left(0.1\right)}^3\left(900\right)(0.5\times {10}^{-2})5$

$=-0.0455$