Question

A 5 N force is applied to a 3kg ball to slow it down from 9 m/s to 3 m/s. What is the impulse on the ball

Answer 1

Impulse = change in momentum = m(vf − vi) = 3(3 − 9) = −18 kg·m/s.

So the impulse is −18 N·s (magnitude 18 N·s) directed opposite the ball's initial motion.