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 × 10⁵ J/kg and g = 10 N/kg]

136 km

Total energy = mgh

ΔQ = mL

\(\frac{1}{4}\)mgh = mL

h = \(\frac{4L}{g}\) = \(\frac{4 × 3.4 × 10^5}{10}\) = 136 x 10³ = 136 km