A ball traveling with an initial momentum of 4.5 kgm/s bounces off a wall and comes back in the opposite direction with a momentum of - 3.5 kgm/s. What is the change in momentum?

-7.5 kg m/s

Explanation:

Initial momentum (p1) = 4.5 kg m/s

final momentum (p2) = - 3.5 kg m/s

We have to find out the change in momentum, As linear momentum is a vector quantity. So, we have to use the vector form to solve the momentum change. Means we have to take the sign of momentum also.

Change in momentum = Final momentum - initial momentum

So,

Change in momentum = p2 - p1

Insert values from question,

Change in momentum = - 3.5 kg m/s - 4 kg m/s

So, change in momentum = - 7.5 kg m/s