Question

A man pushes a lawn mower on a level lawn with a force of 207 N. If 41% of this force is directed forward, how much power does he expend in pushing the mower 4.8 m in 18 s?

Answer 1

The power expended in pushing the mower is equal to the work done divided by the time taken. The work done is equal to the force applied multiplied by the distance moved.

Work = Force x Distance

Work = 207 N x 4.8 m

Work = 997.6 Nm

Power = Work / Time

Power = 997.6 Nm / 18 s

Power = 55.4 W

The man expends 55.4 W of power in pushing the mower 4.8 m in 18 s.