Posted by sam on .
A 0.70 kg ball is moving horizontally with a speed of 8.8 m/s when it strikes a vertical wall. The ball rebounds with a speed of 3.7 m/s. What is the magnitude of the change in linear momentum of the ball?
I am not sure how to honestly to figure this one out.

physics 
bobpursley,
final momentum  initial momentum
m(Vf)m(Vi)= (notice the negative sign in the second velocityk, it is going opposite to final velocity.