Question

in one cycle, an engine burning a mixture of air and methanol (methyl alcohol) absorbs 538 J and expels 338 J. What is the engine's efficiency?

Answer 1

The engine's efficiency is 37.17%, calculated using the formula for efficiency as the ratio of work output (200 J) to the heat input (538 J).

Step-by-step explanation:

The efficiency of an engine is defined as the ratio of the work output to the heat input, typically expressed as a percentage. To calculate the efficiency of an engine that absorbs 538 J and expels 338 J in one cycle, you subtract the heat expelled from the heat absorbed to find the work output and then divide by the heat absorbed. The work output is 538 J absorbed - 338 J expelled = 200 J. Therefore, the efficiency (e) is calculated as:

e = (Work output / Heat input) × 100 = (200 J / 538 J) × 100 = 37.17%

Hence, the engine's efficiency is 37.17%.