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 × ``10^5`` J/kg and
g = 10 N/kg]
(1) 34 km
(2) 544 km
(3) 136 km
(4) 68 km