Collisions, Impulse, and Reference Frames

[sam_amy]

A racquet ball with mass m = 0.245 kg is moving toward the wall at v = 15.4 m/s and at an angle of θ = 28° with respect to the horizontal. The ball makes a perfectly elastic collision with the solid, frictionless wall and rebounds at the same angle with respect to the horizontal. The ball is in contact with the wall for t = 0.069 s.


What is the magnitude of the initial momentum of the racquet ball?
What is the magnitude of the change in momentum of the racquet ball?
What is the magnitude of the average force the wall exerts on the racquet ball?

I've already computed the initial momentum =3.773kgm/s but I honestly can't figure out the second question...
I'm using Favg*delta(t) equals impulse but I can't figure it out
Please help me!

 

[jackarms]

Since, it's hitting the wall at an angle, you'll have to think of it in terms of components. If the wall is vertical, then the object is either moving up or down with some horizontal velocity when it hits it. Think about how the horizontal and vertical components of velocity will change, and thus how the components of momentum will change.

 

[sam_amy]

Ahhhh! Got it! Thank you so much!