Efficiency of a heat engine at high temps

AI Thread Summary
The discussion centers on calculating the maximum efficiency of a heat engine operating between temperatures of 550°C and 365°C. The correct formula for efficiency is identified as η = 1 - (Tc/Th), where Tc is the cold reservoir temperature and Th is the hot reservoir temperature. There is clarification that temperatures must be converted to Kelvin for accurate calculations. The participant confirms their understanding and expresses gratitude for the guidance. The conversation emphasizes the importance of using the correct formula and temperature units in thermodynamic calculations.
notsam
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Homework Statement

What is the maximum effciency of a heat engine whose operating tempuratures are 550oC and 365oC?



Homework Equations

E=1-Thot/Tcold



The Attempt at a Solution

PLEASE HELP! My thinking is that the effciency is equal two one minus the temperature in the hot resavour divided by the temperature in the cold resavour. Is that correct?
 
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notsam said:

Homework Statement

What is the maximum effciency of a heat engine whose operating tempuratures are 550oC and 365oC?



Homework Equations

E=1-Thot/Tcold



The Attempt at a Solution

PLEASE HELP! My thinking is that the efficiency is equal to one minus the temperature in the hot reservoir divided by the temperature in the cold reservoir. Is that correct?
You have it upside down. If it was Th/Tc you would have negative efficiency which makes no sense. The correct expression for efficiency of a Carnot engine is:

\eta = 1 - \frac{T_c}{T_h}

AM
 
Ok :) At least I'm somewhat on the right track. THANKS!
 
I use Kelvin correct?
 
notsam said:
I use Kelvin correct?
Correct.

AM
 

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