A crane lifts two 100 kg loads of building materials to the top of a building under construction. The irst load is lifted in 10 s and the second load is lifted in 13 s. Which of the following statements best compares the work and power expended by the crane lifting the two loads?
A)The crane does more work and expends more power for the irst lift.
B)The crane does the same work and expends the same power for each lift.
C)The crane does the same work for each lift but expends more power for the irst lift.
D)The crane does more work in the second lift but expends the same power for each lift.

Question

Quizplus · Accepted Answer

The work done by the crane in lifting each load is the same because work is defined as force times distance, and both loads are the same weight and lifted the same distance. However, power is defined as work done per unit time. Since the first load is lifted in less time, the crane expends more power on the first lift.

A Crane Lifts Two 100 Kg Loads of Building Materials