Question

A pulley system has an efficiency of 74.2%. If you perform 200 J of work, how much useful work does the pulley perform?

A.200 J
B.148 J
C.52 J
D.113 J

Answer 1

Efficiency is the measure of how efficient a process is. It is used to assess the ability of a process in avoiding waste energy, materials, money and time in doing a desirable output. It is calculated as;

Efficiency = useful energy ouput / total energy input

.742 = useful energy / 200 J
Useful energy = 148.4 J <-----------OPTION B