What Is the Efficiency of a Refrigerator with a COP of 13.8?

AI Thread Summary
A reversible refrigerator with a coefficient of performance (COP) of 13.8 requires the use of specific equations to determine its efficiency. The efficiency can be calculated using the formula Efficiency = (Th - Tc) / Th, while the COP is defined as COP = Tc / (Th - Tc). To solve for efficiency, it's suggested to express both Tc and Th in terms of their ratio. The discussion highlights a common misunderstanding in directly using the COP value. Clarifying these relationships is essential for accurately calculating the efficiency of the refrigerator.
Jennifer_ea
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Homework Statement


The question is simply:
A reversible refrigerator has a coefficient of performance equal to 13.8. What is its efficiency?

Homework Equations


COPrefrigerator = Tc/(Th - Tc)
Efficiency = (Th - Tc) / Th

The Attempt at a Solution



I'm assuming I need to use these equations to solve for efficiency, but I can't figure it out. I tried to just use 1/13.8, but as expected that didn't work. I'm sure it's something basic I'm over looking but I can't see it.
 
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Hint: Express both quantities in terms of the ratio Tc/Th.
 
vela said:
Hint: Express both quantities in terms of the ratio Tc/Th.

ack! Thank-you so much, that was the push I needed
 

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