Multiple Choice
A theoretical heat engine in space could operate between the Sun's 5500°C surface and the –270.3°C temperature of intergalactic space. What would be its maximum theoretical efficiency?
23. The Second Law of Thermodynamics
The Carnot Cycle
Back23. The Second Law of Thermodynamics
The Carnot Cycle
- Multiple Choice
A Carnot engine with an efficiency of 70% is cooled by water at 10°C. What temperature must the hot reservoir be maintained at?
- Multiple Choice
Your friend claims they have a design for a reversible heat engine that can operate between the freezing and boiling temperatures of water that has an efficiency of 30%. Is this possible?
- Multiple ChoiceWhat is the Carnot efficiency of a heat engine operating between a hot reservoir at 300°C and a cold reservoir at 10°C?
- Multiple ChoiceWhat is the hot reservoir temperature of a Carnot heat engine that does work each cycle while expelling to a cold reservoir?
- Open QuestionA Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation, the heat rejected by the engine melts 0.0400 kg of ice. During this time, how much work W is performed by the engine?
- Open QuestionA Carnot engine is operated between two heat reservoirs at temperatures of 520 K and 300 K. (c) What is the thermal efficiency of the engine?
- Open QuestionA Carnot engine is operated between two heat reservoirs at temperatures of 520 K and 300 K. (b) How much mechanical work is performed by the engine during each cycle?
- Open QuestionA Carnot engine is operated between two heat reservoirs at temperatures of 520 K and 300 K. (a) If the engine receives 6.45 kJ of heat energy from the reservoir at 520 K in each cycle, how many joules per cycle does it discard to the reservoir at 300 K?
- Open QuestionWhich, if any, of the heat engines in FIGURE EX21.22 violate (a) the first law of thermodynamics or (b) the second law of thermodynamics? Explain.
- Open QuestionAt what cold-reservoir temperature (in ℃) would a Carnot engine with a hot-reservoir temperature of 427℃ have an efficiency of 60%?
- Open QuestionA Carnot engine whose hot-reservoir temperature is 400℃ has a thermal efficiency of 40%. By how many degrees should the temperature of the cold reservoir be decreased to raise the engine's efficiency to 60%?
- Open QuestionThe engine that powers a crane burns fuel at a flame temperature of 2000℃. It is cooled by 20℃ air. The crane lifts a 2000 kg steel girder 30 m upward. How much heat energy is transferred to the engine by burning fuel if the engine is 40% as efficient as a Carnot engine?
- Open QuestionA Carnot heat engine operates between reservoirs at 182℃ and 0℃. If the engine extracts 25 J of energy from the hot reservoir per cycle, how many cycles will it take to lift a 10 kg mass a height of 10 m?