A tennis ball of mass m = 0.065 kg and speed v = 25 m/s strikes a wall at a 45° angle and rebounds with the same speed at 45° (Fig. 7-29). What is the impulse given the wall?

I started out with finding the momentum and doubling it to get the impulse on the wall but that isn't the right answer. What equation do I need to start this one? Does it have to do with the angles they are giving me?

1 answer

No, that is not right. Only the normal component doubles.

Vfinalnormal =25*.707*2

Force*time=m*vfinalnormal
You have to only dealt with what changed, the momentum normal, and the implulse norma.