A car engine whose output power is 155 hp operates at about 15% efficiency. Assume the engine’s water temperature of 95°C is its соld-temperature (exhaust) reservoir and 495°C is its thermal “intake” temperature (the temperature of the exploding gas–air mixture). ( a ) What is the ratio of its efficiency relative to its maximum possible (Carnot) efficiency? ( b ) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.
A car engine whose output power is 155 hp operates at about 15% efficiency. Assume the engine’s water temperature of 95°C is its соld-temperature (exhaust) reservoir and 495°C is its thermal “intake” temperature (the temperature of the exploding gas–air mixture). ( a ) What is the ratio of its efficiency relative to its maximum possible (Carnot) efficiency? ( b ) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.
A car engine whose output power is 155 hp operates at about 15% efficiency. Assume the engine’s water temperature of 95°C is its соld-temperature (exhaust) reservoir and 495°C is its thermal “intake” temperature (the temperature of the exploding gas–air mixture). (a) What is the ratio of its efficiency relative to its maximum possible (Carnot) efficiency? (b) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.
A car engine whose output power is 135 hp operates atabout 15% efficiency. Assume the engine’s water temperature of 85°C is its cold-temperature (exhaust) reservoir and 495°C is its thermal “intake” temperature (the temperature of the exploding gas–air mixture). (a) What is the ratio of its efficiency relative to its maximum possible (Carnot)efficiency? (b) Estimate how much power (in watts) goes into moving the car, and how much heat, in joules and in kcal, is exhausted to the air in 1.0 h.
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 depth of about 1 km). (a) What is the maximum efficiency of such a system? (b) If the useful power output of the plant is 75.0 MW, how much energy is absorbed per hour? (c) In view of your answer to part (a), do you think such a system is worthwhile (considering that there is no charge for fuel)?
As a gasoline engine is running, an amount of gasoline containing 15,000J of chemical potential energy is burned in 1 s. During that second, the engine does 3,000 J of work.
(b) The burning gasoline has a temperature of about 2500 K. The waste heat from the engine flows into air at about 300 K. What is the Carnot efficiency of a heat engine operating between these two temperatures?
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The Second Law of Thermodynamics: Heat Flow, Entropy, and Microstates; Author: Professor Dave Explains;https://www.youtube.com/watch?v=MrwW4w2nAMc;License: Standard YouTube License, CC-BY