Answer: 0.37 m/s2
Step-by-step explanation:
This is a Newton's 3rd Law of Motion problem. The force exerted on the pin by the ball is equal and opposite to the force exerted by the pin on the ball. F = ma
let x = acceleration of the ball after it hits the pin
(4.5 kg)(x) = (0.25 kg)(6.6 m/s2)
x = ((0.25 kg)(6.6 m/s2)) / (4.5 kg) = 1.65 / 4.5 = 0.37 m/s2