A refrigerator removes heat from the freezing compartment at the rate of20 kJ per cycle and ejects 24 kJ into the room each cycle. How much energy is used in each cycle?

Question

Physics

Conrad Buchanan

6 May, 19:40

A refrigerator removes heat from the freezing compartment at the rate of20 kJ per cycle and ejects 24 kJ into the room each cycle. How much energy is used in each cycle?

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Answers (1)

Know the Answer?

Damari Jones · Answer 1

Energy used = 4KJ

Explanation:

Second law of thermodynamics states that as energy is transferred or transformed, more and more of it is wasted. The Second Law also states that there is a natural tendency of any isolated system to degenerate into a more disordered state.

Now when we apply that to heat engines, we'll see that;

Heat expelled = Heat removed + Work Done

We can write it as;

Q_h = Q_c + W

We are given that;

Heat removed; Q_c = 20KJ

Heat expelled into the room in each cycle; Q_h = 24KJ

Thus; plugging these 2 values into the equation, we obtain;

24 = 20 + W

W = 24 - 20

W = 4 KJ

Work done is energy used.

Thus, energy used = 4 KJ