A 5 N force is applied to a 3 kg ball to change its velocity from 9 m/s to 3 m/s. What is the impulse on the ball?

So, first the formula of Impulse is

I = force * time

We have force but no time.

Then, find time.

Next find acceleration,

F = mass * acceleration

5 = 3 * a

1.67 m/s^2

Next find time,

Acceleration = change in velocity / time

Change in velocity is velocity final - velocity initial

1.67 = 3 - 9 / time

Time = 3.6 s (round to 2 s. f.)

Lastly,

Impulse = force * time

Impulse = 5 * 3.6

Impulse is 18 Ns