Heat Engine Efficiencies

  • #1
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Homework Statement


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Suppose you build a steam engine that exhausted 1000 J of thermal energy while performing 300 J of work. What is the energy input? What is the efficiency?


Homework Equations




The Attempt at a Solution



Would this be correct?


Thermal E Input = work + exhaust = 300 J + 1000 J = 1,300 J




Efficiency = work output / thermal energy input = 300 J / 1,300 J = 0.231 J


 

Answers and Replies

  • #2
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The efficiency does not have units of Joules. It does not have any units, it's a ratio.
 
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  • #3
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The efficiency does not have units of Joules. It does not have any units, it's a ratio.
Thanks!
 

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