Question

A hockey puck is pushed by a stick with a force of 750 newtons. The puck travels 2.0 meters in 0.30 seconds. How powerful is the push?

1,500 W
5,000 W
112 W
450 W

Answer 1

Power, P = Force, F * Velocity, V

V = distance/time = 2/0.3 = 6.67 m/s

Therefore,
P = 750*6.67 = 5000 W

Answer 2

The work done to push the puck is the product between the force F and the distance d:

`W=Fd=(750 N)(2.0 m)=1500 J`

And the power is the work done (W) per unit time (t):

`P=(W)/(t)`

Substituting the work done, W=1500 J, and the time taken, t=0.30 s, we find the power of the push:

`P=(1500 J)/(0.30 s)=5000 W`