Need Help Solving for Work Done: 60,000 J

L In summary, the question is about finding the correct amount of work done in a gas compression process and the correct answer is 60,000 J according to the book. The conversation discusses various calculations and conversions, ultimately leading to the realization that the conversion factor may be approximated as 1:100. Therefore, the original calculation of work done by the gas on the surroundings is corrected to 3.5 atm and the answer is very close to the expected 60,000 J.
  • #1
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All, I need some direction on the following question, please.
Correct answer is 60,000 J according to book.

Here's what I have so far, but it may be incorrect: Work done C-->D is (2 atm)(-400 L)(101) = -81,000 J, so work was done on the system when the gas was compressed. No work is done D-->A. Lastly, work done A-->C is (3 atm)(400 L)(101) = 121,200 J. This is work done by the gas on the surroundings. As you can see, my figures do not get to 60,000 J! Thanks in advance. Hopefully I haven't done anything too stupidly obvious!
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  • #2
For A-->C, why did you use 3atm? Shouldn't it be the average pressure?
 
  • #3
units for pressure should be Pa and units for volume should be m3
 
  • #4
The conversion was handled with the (101) term.
1 L-atm = 101.325 J
Perhaps the problem assumes a simpler conversion factor of approx. 1:100.
 
  • #5
Yes, it should be 3.5 atm and this gets me very close to the 60,000 J answer. Thank you.
 
  • #6
RUber said:
The conversion was handled with the (101) term.
1 L-atm = 101.325 J
Perhaps the problem assumes a simpler conversion factor of approx. 1:100.
RUber said:
The conversion was handled with the (101) term.
1 L-atm = 101.325 J
Perhaps the problem assumes a simpler conversion factor of approx. 1:100.

sorry...I see that the units were taken care of 103 x 10-3
 

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