Question

A heat engine does 30 j of work per cycle while exhausting 50 j of waste heat. what is the engine's thermal efficiency?

Answer 1

The engine's thermal efficiency, which is the proportion of heat energy converted to work, is calculated as 37.5% using the formula η = (Work output / Heat input) × 100.

Step-by-step explanation:

The student has asked about the thermal efficiency of a heat engine. Thermal efficiency is a measure of the portion of heat energy converted into work as compared to the total heat energy entered into the system. To calculate the thermal efficiency (η), we can use the formula:

η = (Work output / Heat input) × 100

In this scenario, the work output is 30 J per cycle, and the total heat input is the work done plus the waste heat, which is 30 J + 50 J = 80 J. Therefore, the efficiency is:

η = (30 J / 80 J) × 100 = 37.5%

The engine's thermal efficiency is 37.5%.

Answer 2

37.5%

Step-by-step explanation:

Add your work per cycle and waste: 30 + 50 = 80

Then divide work per cycle by your new value: 30/80 = 0.375

37.5%