Answer:
148.4 J
Explanation:
We are given that the efficiency of a pulley system is 74.2% and we are to calculate the useful work done if we perform 200 J of work
We know that efficiency is basically the measure of how efficient a process is.
The formula of efficiency is given by:
Efficiency = useful energy output / total energy input
So substituting the given values in the above formula:
0.742 = Useful energy / 200 J
Useful energy = 148.4 J
