proving efficiency

[jlmac2001]

I'm having trouble with proving the following question. Can someone please help, please.

(1) Prove that if you had a heat engine whose efficiency was better than the ideal value (4.5) you could hook it up to an ordinary Carnot refrigerator to make a refrigeratior that requires no work input.


I know that efficency = 1-Qc/Qh and COP=1/(Qh/Qc - 1)but how do i prove the above question?

[turin]

Originally posted by jlmac2001
... if you had a heat engine whose efficiency was better than the ideal value (4.5) ...Either I'm really ignorant of this thermo stuff, or you've gotten the wrong number for efficiency. I think it should always be less than unity.




Originally posted by jlmac2001
... you could hook it up to an ordinary Carnot refrigerator ...My first step would be to draw a diagram. Make sure to include the hot and cold reservoirs and the directions of energy/heat flow. That should give a good picture of what's going on.