A 3 kg ball with an initial velocity = (4.00i + 3.00j)m/s collides with a wall and rebound with a final velocity = (-4.00i + 3.00j)m/s. The ball is in contact with the wall for delta t =2.00E-3s. (specify answers with unit vectors)

Question

A 3 kg ball with an initial velocity = (4.00i + 3.00j)m/s collides with a wall and rebound with a final velocity = (-4.00i + 3.00j)m/s. The ball is in contact with the wall for delta t =2.00E-3s. (specify answers with unit vectors)

a) what is the change in the ball's momentum? ans -24i + 0j

b)what is the impulse exerted on the ball by the wall?
ans mvf - mvi = 0 - (-24i) = 24 kgm/s (is this correct?)

c) what is the average force on the ball by the wall?

ans Favg = impulse/t
so: Favg = 24kgm/s / 2E-3 = 1.2E4 (newton?)

d) what is the average force on the wall by the ball?

??

What is your question? THe last part, is opposite sign to c).

so it appears, I was on the right direction? therefore both a) b) c) are correct and that for d) I'll have opposite negative response to C.

yes, they are all correct.

Answer 1

Yes, you are correct in your understanding of parts a), b), and c). For part d), since the ball exerts a force on the wall, the force exerted by the wall on the ball will be equal in magnitude but opposite in direction. Therefore, the average force on the wall by the ball would be -1.2E4 Newtons, in the opposite direction of the force exerted by the ball on the wall.