Question

If the work output of a simple machine is 40 J and the work input is 50 J, the percent efficiency is _____%.

A. 5/4
B. 10
C. 80
D. 90​

Answer 1

Efficiency = (Work out / Work In) * 100

Efficiency = (40 / 50) * 100

Efficiency = 0.8 * 100

Efficiency = 80%

The efficiency of any machine has to be less than 100%. If it is not, patent whatever you are doing. It will make you instantly wealthy.