A boy holds a 40-N weight at arm's length for 10 s. His arm is 1.5 m above the ground. The work done by the force of the boy on the weight while he is holding it is:

Question

Quizplus · Accepted Answer

The work done by a force is equal to the force multiplied by the displacement in the direction of the force. In this case, the boy is holding the weight still, so there is no displacement in the direction of the force. Therefore, the work done by the force of the boy on the weight is zero.

A Boy Holds a 40-N Weight at Arm's Length for 10