First law of thermodynamics: A system has a heat source supplying heat to an ideal gas at a rate of 187.0 W and the gas is doing work at a rate of 130.9 W. At what rate is the internal (thermal) energy of the gas changing?

Question

Quizplus · Accepted Answer

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. Here, the rate of change of internal energy = rate of heat supplied - rate of work done = 187.0 W - 130.9 W = 56.1 W.

First Law of Thermodynamics: a System Has a Heat Source