Worksheet: Heat Engines
In this worksheet, we will practice calculating the work extracted by heat engines from the transfer of heat from high to low temperature reservoirs.
A Carnot engine has an efficiency of 0.500. The temperature of the engine’s cold reservoir changes and its efficiency drops to 0.450. The initial temperature of the cold reservoir is . The temperature of the hot reservoir does not change.
What is the temperature of the hot reservoir?
What is the temperature of the cold reservoir after its temperature changes?
An engine operating between heat reservoirs at temperatures of and extracts 1,000 J per cycle from the engine’s hot reservoir. In modeling the heat flow in the engine, use three-significant-figure precision.
What is the maximum possible work that engine can do per cycle?
What is the minimum heating of the cold reservoir per cycle?
A heat engine operates between two temperatures such that the working substance of the engine absorbs 5,000 J of heat from the high-temperature bath and rejects 3,000 J to the low-temperature bath. The rest of the energy is converted into mechanical energy of the turbine.
Find the amount of work produced by the engine.
Find the efficiency of the engine.
A Carnot engine is used to measure the temperature of a heat reservoir. The engine operates between the heat reservoir and a reservoir consisting of water at its triple-point.
If 400 J per cycle are removed from the heat reservoir while 200 J per cycle are deposited in the triple-point reservoir, what is the temperature of the heat reservoir?
If 400 J per cycle are removed from the triple-point reservoir while 200 J per cycle are deposited in the heat reservoir, what is the temperature of the heat reservoir?
A heat engine has an efficiency of 0.333. The high-temperature reservoir temperature is a constant . What is the low-temperature reservoir temperature in ? Answer to three significant figures.
A heat engine has constant reservoir temperatures of 2,000 K and 200 K.
What is the maximum efficiency of the engine? Answer to three significant figures.
The low-temperature reservoir is heated by 452 J. How much work is done by the heat engine? Answer to three significant figures.