College Physics with MasteringPhysics 7th Edition by Jerry Wilson,Anthony Buffa,Bo Lou

Exercise 42

A salesperson tells you that a new refrigerator with a high COP removes 2.6 × 10 3 J (each cycle) from the inside of the refrigerator at 5.0 °C and expels 2.8 × 10 3 J into the 30 °C kitchen, (a) what is the refrigerator's COP (b) Is this scenario possible Justify your answer. (See Exercise.)
Exercise
There is a Carnot coefficient of performance (COP C ) for an ideal, or Carnot, refrigerator. (a) Show that this quantity is given by

(b) What does this tell you about adjusting the temperatures for the maximum COP of a refrigerator (Can you guess the equation for the COP C for a heat pump )