Please help with these two questions Exercise 20.9 A refrigerator has a coeffici

Question

Please help with these two questions

Exercise 20.9 A refrigerator has a coefficient of performance of 2.30. Each cycle it absorbs 3.94x104 J of heat from the cold reservoir Part A How much mechanical energy is required each cycle to operate the refrigerator? Express your answer with the appropriate units. IWI Value nits Submit My Answers Give Up Part B During each cycle, how much heat is discarded to the high-temperature reservoir Express your answer with the appropriate units. IQHI Value Units Submit My Answers Give Up

Explanation / Answer

Part-A : Mechanical energy required for each cycle to operate the refrigerator which is given as -

using a formula, we have

COP = Qc / | W |

where, Qc = heat from the cold reservoir = 3.94 x 104 J

then, we get

(2.3) = (3.94 x 104 J) / | W |

| W | = (3.94 x 104 J) / (2.3)

| W | = 1.71 x 104 J

Part-B : During each cycle, heat discarded to the high-temperature reservoir which is given as -

using a formula, we have

| W | = QH - QC

(1.71 x 104 J) = QH - (3.94 x 104 J)

QH = 5.65 x 104 J

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