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Homework Help: Thermodynamics homework help

  1. Apr 10, 2012 #1
    1. The problem statement, all variables and given/known data

    Part B

    2. Relevant equations

    Thermodynamics, Carnot cycle, ts diagram

    3. The attempt at a solution

    I understand that for figure A, Qh=T1Δs and Qc=(T1-T2)Δs once you take the negative out of the Δs. For figure B, Qh=(T2-T1)Δs and Qc=-T2Δs once you take the negative out of the Δs. For the efficiency of figure A, I got η=T2/T1 after plugging into 1-Qc/Qh. For figure B, I got η=(2T2-T1)/(T2-T1). I have a feeling that what I have for figure A is right but that B is no where close. Any help would be awesome

    Attached Files:

  2. jcsd
  3. Apr 11, 2012 #2

    Andrew Mason

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    Science Advisor
    Homework Helper

    Re: Thermodynamics

    Keep in mind that efficiency is given by:

    η = W/Qh

    and W = Qh-Qc.

    What is W and Qh in terms of the areas under these graphs? Hint: What is the area under a sloping line?

    Is there a difference between A and B in terms of W? How about in terms of Qh?

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