(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A ball of mass m moving with velocity v strikes a vertical wall. The angle between the ball's initial velocity vector and the wall is theta_i as shown on the diagram, which depicts the situation as seen from above. The duration of the collision between the ball and the wall is Δt, and this collision is completely elastic. Friction is negligible, so the ball does not start spinning. In this idealized collision, the force exerted on the ball by the wall is parallel to the x axis.

A)What is the final angle theta_f that the ball's velocity vector makes with the negative y

B)What is the magnitude F of the average force exerted on the ball by the wall? (Express your answer in terms of variables given in the problem introduction and/or Vix)

http://session.masteringphysics.com/problemAsset/1010992/31/MLM_e2.jpg

3. The attempt at a solution

A)= theta_i

B)i dont really know where to start. i broke down the final velocity vector into its x and y components. (Vi=velocity initial) Vix=Visin θi, Viy=-Vicosθi, Vfx=-Vfsinθf, Vfy=-Vfcosθf. since the collision is elastic i cant use ΔP=J because the momentum before is the same as after. i feel like somewhere i am suppose to use the equation J=FΔt, but i cant figure it out.

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# Homework Help: Elastic collision angle

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