A refrigerator converts 100 g of water at 20oC to ice at - 10oC in 73.5 min. Calculate the average rate of heat extraction in Watt. The specific heat capacity of water is 4.2Jg−1K−1, specific latent heat of ice is 336Jg−1 and the specific heat capacity of ice is 2.1Jg−1K−1