# Homework Help: Thermodynamics homework help

1. Apr 10, 2012

### 26xc37

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

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2. Apr 11, 2012

### Andrew Mason

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?

AM