A crane motor exerts 3,500 W to lift a load up 5 floors in 25 seconds. How much work did the crane do?

Answer: 87500J

Explanation:

Given that,

Power exerted by crane = 3,500 W

Time taken = 25 seconds

work done by crane = ?

Since power is the rate of work done per unit time, then power is workdone by the crane divided by the time taken.

i. e power = work / time

3,500 W = work / 25 seconds

Work = 3500W x 25 seconds

Work = 87500J

Thus, 87500 joules of work was done by the crane.