Total angle of deflection

If there were two walls perpendicular to each other, and a ball collided with each wall, how would you find the total angle of deflection?

Elastic collision - it should reverse the direction? Could you upload the question if there is one.

Did you sketch it / work it out? Its not totally elastic collisions, but the first collision gives the coefficient of restitution.

I agree with the sketch (maybe make the scaling a bit more clear), so what are you unsure about?

When I last did this question, I didn't get the total angle of deflection as 180 degrees (it seems obvious behind the diagram but when I did the calculation I got it wrong). But when I did it now I got 180 degrees. So if there are two collisions like this would the total angle of deflection always be 180, or does it depend on the coefficient of restitution?

If you do the velocities as vectors
(5,-4) -> (5,4e) -> (-5e,4e) = -e(5,-4)
so its always parallel to the original vector, but scaled by e and in the opposite direction, so deflection is always 180 and e just affects the magnitude or ke.
You could draw a horizontal line through the second collision point and note that that angle must be alpha as well as you mulitply each component by e (1/2) so tan() of both angles is the same.