A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.40×10^−2 kg. Throughout this problem use L_f = 3.34x10^5 J/kg for the heat of fusion for water. During this time, how much work W is performed by the engine? I dont know where to start...any help please?