PROBLEMS TO BE WRITTEN UP AND TURNED IN AT RECITATION

     This problem is due at the beginning of lecture on Fri 04/22.  The 
     problem should be written on a single sheet of paper (front and back), 
     or if multiple sheets are used, staple them together.  For full credit,
     the work must be neat, with clearly labeled diagrams (if useful).  The 
     labels must be in BOTH words and symbols.  For each part of the problem, 
     you must BRIEFLY explain your strategy in words, as well as neatly 
     showing your physics equations and math, with proper units. 

               Wolfson Chapter 22 problem 63, p. 567. (10 points)

     GBA notes that Wolfson uses the same COP for both heat pump and
     refrigerator.  Let's instead use Q_H/W for the COP of a heat pump;
     so our answers for parts (a) and (b) will be different from the
     answers in the back of Wolfson.  Also, note that to do this problem
     with the given information, we must assume that our heat pumps have
     the Carnot COP; the actual COP will of course be smaller.