Question

A 0.2 kg hockey puck is sliding along the ice with an initial velocity of -10 m/s when a player strikes with his stick, causing it to reverse it's direction and giving it a velocity of +25 m/s. The impulse the stick applies to the puck is most nearly

Answer 1

I = 7 N-s

Explanation:

Impulse is defined as

I = ∆p = m(vf - vi)

We are given

m = 0.2 kg

vi = -10 m/s (to the left)

vf = +25 m/s (to the right)

Therefore, the impulse imparted on the puck is

I = (0.2 kg)[25 m/s - (-10 m/s)]

= (0.2 kg)(35 m/s)

= 7 N-s