Explanation:
The first bit of information we need for this question is the DHfusion of water at 1 atm and 0°C; this is not a number that you need memorize, rather you may find it easily in many references under "heat of fusion of water." DHfusion= 334 kJ/kg. Next, we need the definition of the Coefficient of Performance for a refrigeration system; COP = Q/W, where Q is the heat removed and W is the work expended; you should familiarize yourself with this definition. So for this question, W = Q/COP = 1000 lb/day (1 day/24 hours) (1 hour /3600 sec) (1 kg/2.24 lb)(334 kJ/kg) (1/3.5) = 493 W.
