Question

A heat engine takes in 1000J of heat from a high temperature reservoir at 600K and exhaust 600 J of heat to a low temperature reservior at 400K. What is the efficiency of the engine?

Answer 1

The efficiency of a heat engine can be calculated using the following formula:

Efficiency = (Useful work output) / (Heat input)

In this case, the useful work output is the difference between the heat input and the heat exhaust. The heat input is given as 1000 J, and the heat exhaust is given as 600 J.

Useful work output = Heat input - Heat exhaust Useful work output = 1000 J - 600 J Useful work output = 400 J

Now we can calculate the efficiency:

Efficiency = (Useful work output) / (Heat input) Efficiency = 400 J / 1000 J

To get the value in percentage, we can multiply by 100:

Efficiency = (400 J / 1000 J) * 100 Efficiency = 40%

Therefore, the efficiency of the heat engine is 40%.