A carnot refrigerator takes heat from water at 0 degrees Celsius and rejects heat to a room temperature at 20 degrees Celsius. Assume that 78 grams of water at 0 degrees Celsius are converted to ice at 0degrees Celsius by the refrigerator. Compute the mechanical energy that should be supplied to the refrigerator. (Note: The heat fusion of water is 3.34 x10^5 J/kg)