Question
In Figure 15.44, which of the following cycles has the greatest net work output?
  1. ABDA
  2. BCDB
  3. (a) and (b) are equal
  4. ADCBA
<b>Figure 15.44</b>
Figure 15.44
Question by OpenStax is licensed under CC BY 4.0
Final Answer

(d)

Solution video

OpenStax College Physics for AP® Courses, Chapter 15, Problem 11 (Test Prep for AP® Courses)

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Video Transcript
This is College Physics Answers with Shaun Dychko. The greatest net work output occurs for the process that has the greatest in area enclosed by its loop. So if we consider the process ABDA, the area enclosed is this yellow triangle. For the process BCDB, the total area enclosed is this much. But if you include ADCBA, then this process would include the entire area in purple. And so, for that reason, it is the process with the greatest net work output. So the answer is D.

Comments

Question: Doesn't the direction matter? ABDA and BCDB are both clockwise processes (positive work); whereas, ADCBA is counter-clockwise (negative work). Or am I in error with my thinking?