What is the best coefficient of performance for a heat pump

Last updated: 7/6/2022

What is the best coefficient of performance for a heat pump with a hot reservoir of 50°C and a cold reservoir of -20°C? b. How much heat transfer occurs into the warm environment if 3.6*107 J of work is put into the system? c. If the cost of this work is 25 cents per 107 J of work, what would be the cost for the heat cost for the heat in part b? d. How would this cost compare to burning natural gas directly for heat (not a heat pump) if that work cost 8 cents per 10^7 J of work?