Heat engines: A heat engine with an efficiency of 30.0% performs 2500 J of work. How much heat is discharged to the lower temperature reservoir?
A) 5830 J
B) 8330 J
C) 750 J
D) 1350 J
E) 7080 J

Question

Quizplus · Accepted Answer

The efficiency of a heat engine is given by the ratio of work output to heat input, which is 30% or 0.30 in this case. If the engine performs 2500 J of work, the heat input (Q_in) can be calculated as work divided by efficiency: Q_in = 2500 J / 0.30 = 8333.33 J. The heat discharged (Q_out) is the difference between the heat input and the work output: Q_out = Q_in - Work = 8333.33 J - 2500 J = 5833.33 J, which is approximately 5830 J.

Heat Engines: a Heat Engine with an Efficiency of 30