An ice-making machine operates in a Carnot cycle. It takes heat from water at 0.0 oC and rejects heat to a room at 24.0 oC. Suppose that 85.0 kg of water at 0.0 oC are converted to ice at 0.0 oC. How much energy (in Joules) must be supplied to the machine to achieve this task? Sol. Since the machine is a operating in a Carnot cycle, then, its efficiency is e = ______ - |______/TH| By virtue of first law, the work done to convert water to ice is given by W = Q = ________ Thus, the total energy needed to convert 85 kg of water is ET = _____687.5 J

An ice-making machine operates in a Carnot cycle. It takes heat from water at 0.0 oC and rejects heat to a room at 24.0 oC. Suppose that 85.0 kg of water at 0.0 oC are converted to ice at 0.0 oC. How much energy (in Joules) must be supplied to the machine to achieve this task? Sol. Since the machine is a operating in a Carnot cycle, then, its efficiency is e = - |/TH| By virtue of first law, the work done to convert water to ice is given by W = Q = Thus, the total energy needed to convert 85 kg of water is ET = _687.5 J