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Homework Help: Proving efficiency

  1. Feb 29, 2004 #1
    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?
  2. jcsd
  3. Mar 1, 2004 #2


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    Homework Helper

    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.

    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.
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