230k views
5 votes
A gust of wind pushes a beach ball with a force of 9 newtons. The ball rolls 10 meters in 3 seconds. What is the power of the wind? 900 W 90 W 30 W 3 W

2 Answers

2 votes

Work done = (force) x (distance)

Work done = (9 Newtons) x (10 meters) = 90 Joules

Power = (work done) / (time to do the work)

Power = (90 Joules) / (3 seconds)

Power = 30 watts

The wind has a lot more power than that. The ball robbed 30 watts from the wind.

If the ball had a different shape, or had smoother or rougher skin, or were lighter or heavier, it might have robbed more power from the same wind.

This it the kind of problem engineers have to solve in order to build a windmill that can extract the most power from the wind.

User Johannes Passing
by
4.8k points
6 votes

P=f*d/t

=9*10/3

=30W

hence power is 30W

User ShashwatZing
by
5.2k points