Question

In performing 100.0 J of work, an engine discharges 50.0 J of heat. What is the efficiency of the engine?

a) 0.33
b) 0.50
c) 0.67
d) 1.00

Answer 1

The efficiency of the engine is calculated by dividing the work output by the heat input. With a work output of 100.0 J and a heat input of 150.0 J, the engine's efficiency comes out to 0.67 or 67%. Therefore, the correct answer is c) 0.67.

Step-by-step explanation:

To calculate the efficiency of the engine, we use the formula:

Efficiency (e) = Work output / Heat input

In this case, the work output is 100.0 J and the heat input is the sum of work output and heat discharged, which is 100.0 J + 50.0 J = 150.0 J.

So, the efficiency calculation will be:

e = 100.0 J / 150.0 J = 0.67

This means the efficiency of the engine is 0.67, or 67%, which corresponds to option c) 0.67.

Engine efficiency refers to how effectively an engine converts energy from a fuel into useful work. It's typically measured by the ratio of the engine's output (useful work or power) to its input (energy from the fuel).