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!