Question

A piece of ice falls from a height h so that it melts completely. Only one-quarter of the heat produced is absorbed by the ice and all energy of ice gets converted into heat during its fall. The value of h is : [Latent heat of ice is $3.4 \times 10^5 \, J/kg$ and $g = 10 \, N/kg$]

• A. 544 km
• B. 136 km
• C. 68 km
• D. 34 k m

Answer 1

Answer: (B)

136 km

Answer 2

$\frac{mgh}{4} = mL$
$\Rightarrow h = \frac{4L}{g} = \frac{4 \times3.4 \times10^{5}}{10} = 136 \, km$