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Ch 20: The Second Law of Thermodynamics

Chapter 20, Problem 20

A diesel engine performs 2200 J of mechanical work and discards 4300 J of heat each cycle. (a) How much heat must be supplied to the engine in each cycle?

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welcome back everybody. We are looking at a gasoline engine inside of a car that converts chemical energy to mechanical energy. We are told that the amount of heat and jewels that is kind of rejected or ejected from the exhaust per cycle is 3500 jewels. And we are told that the work done by the engine is 1700 jewels. And we need to figure out how much heat should be supplied to the engine in order for this cycle to work well, work is just equal to the absolute value of the heat supplied minus the absolute value of the heat that will be ejected and rejected from the system. We add Q. C. To both sides. These terms are going to cancel out and we get that are absolute value of Q. H. Is equal to work plus the absolute value of our Q. C. So let's go ahead and plug in our numbers here. That our work is 1700 jewels plus the absolute value of the heat rejected. Which when you plug this in your calculator, you get that. The heat needed or the heat that should be supplied is 5200 jewels corresponding to our answer. Choice of Thank you all so much for watching. Hope This video helped. We will see you all in the next one
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