A question about refrigerators and energy

AI Thread Summary
The coefficient of performance (COP) of the refrigerator is 5.40, and the compressor uses 30.0 J of energy per cycle, resulting in an exhausted heat energy of 192 J per cycle. The discussion focuses on calculating the lowest possible temperature of the cold reservoir given a hot-reservoir temperature of 27.0°C. The user is struggling with part b of the problem and seeks clarification on the relationship between COP, heat absorbed (Qc), heat exhausted (Qh), and work input (W). Understanding these relationships is crucial for solving the temperature calculation correctly. The thread emphasizes the importance of applying the correct equations to find the solution.
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Homework Statement



The coefficient of performance of a refrigerator is 5.40. The compressor uses 30.0 J of energy per cycle.

a) How much heat energy is exhausted per cycle?
b) If the hot-reservoir temperature is 27.0C, what is the lowest possible temperature in C of the cold reservoir?

Homework Equations



K=TC/(TH-TC)

QH = QC + Win

The Attempt at a Solution



solved part a) and found the energy to be 192 J

i keep on getting part b) wrong though and I ran out of chances to try.

please help!
 
Physics news on Phys.org
What is the COP (coefficient of performance) in terms of Qh, Qc, and/or W?
 

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