Long long ago, In the northern part of Russia where water is available in the form of ice. To drink water people devise some mechanical kind of instrument to prepare water from ice.

First they put ice into a pocket which is made by skin of animal whose heat capacity is negligible and put the system on the ground. With some mechanical arrangement they lift a heavy stone of mass 50 kg upto a height of 2.1 m and released so that it falls free under gravity and strikes to ice which is kept in animal skin pocket. The loss in potential energy in this process goes into the ice in the form of heat. This process is repeated till the whole ice is melted and raised to required temperature. Time taken in one complete cycle of lifting the stone for 2.1 m and falling it on the ice is termed as time period for the process. Under the given observation answer the following questions.

(g = 10 m/s 2 , L f = 3.36 × 10 5 )

(i) If time period is 2 sec then amount of ice at 0ºC melted in 1 minute is (All loss in energy goes to ice)