A golf club exerts an average force of 1000 N on a 0.045-kg golf ball which is initially at rest. The club is in contact with the ball for 1.8 ms. What is the speed of the golf ball as it leaves the tee?
A) 30 m/s
B) 35 m/s
C) 40 m/s
D) 45 m/s
E) 50 m/s

Question

Quizplus · Accepted Answer

We can use the impulse-momentum theorem to solve for the final velocity of the golf ball.

Impulse = change in momentum

Impulse = FΔt = (1000 N)(0.0018 s) = 1.8 Ns

Momentum before = 0 kg m/s (since the ball is at rest) 
Momentum after = mv

Therefore,

Impulse = Momentum after - Momentum before

1.8 Ns = mv - 0

v = (1.8 Ns) / (0.045 kg) = 40 m/s

So the final speed of the golf ball is 40 m/s. Therefore, the answer is choice C.

A Golf Club Exerts an Average Force of 1000 N