Questions from College Physics


Q: A heat pump has a coefficient of performance of 3.80

A heat pump has a coefficient of performance of 3.80 and operates with a power consumption of 7.03 x 103 W. (a) How much energy does the heat pump deliver into a home during 8.00 h of continuous opera...

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Q: A freezer has a coefficient of performance of 6.30.

A freezer has a coefficient of performance of 6.30. The freezer is advertised as using 457 kW-h/y. (a) On average, how much energy does the freezer use in a single day? (b) On average, how much therma...

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Q: Two heat engines are operated in series so that part of the

Two heat engines are operated in series so that part of the energy expelled from engine A is absorbed by engine B with |QhB| = 0.750|QcA|. Engines A and B have efficiencies eA = eB = 0.250 and engine...

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Q: In one cycle a heat engine absorbs 500 J from a high

In one cycle a heat engine absorbs 500 J from a high-temperature reservoir and expels 300 J to a low- temperature reservoir. If the efficiency of this engine is 60% of the efficiency of a Carnot engin...

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Q: A power plant has been proposed that would make use of the

A power plant has been proposed that would make use of the temperature gradient in the ocean. The system is to operate between 20.0°C (surface water temperature) and 5.00°C (water temperature at a dep...

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Q: A certain nuclear power plant has an electrical power output of 435

A certain nuclear power plant has an electrical power output of 435 MW. The rate at which energy must be supplied to the plant is 1420 MW. (a) What is the thermal efficiency of the power plant? (b) At...

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Q: Given three light-bulbs and a battery, sketch as many

Given three light-bulbs and a battery, sketch as many different circuits as you can.

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Q: A heat engine operates in a Carnot cycle between 80.0

A heat engine operates in a Carnot cycle between 80.0°C and 350°C. It absorbs 21000 J of energy per cycle from the hot reservoir. The duration of each cycle is 1.00 s. (a) What is the mechanical power...

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Q: A Styrofoam cup holding 125 g of hot water at 1.

A Styrofoam cup holding 125 g of hot water at 1.00 x 102°C cools to room temperature, 20.0°C. What is the change in entropy of the room? (Neglect the specific heat of the cup and any change in tempera...

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Q: A 65-g ice cube is initially at 0.0

A 65-g ice cube is initially at 0.0°C. (a) Find the change in entropy of the cube after it melts completely at 0.0°C. (b) What is the change in entropy of the environment in this process? Hint: The la...

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