1. The problem statement, all variables and given/known data A ball moving parallel to the y axis undergoes an elastic collision with a parabolic mirror y^2=2px.Prove that no matter where the prompt of impact lies it will arrive at the mirror's focus. 2. Relevant equations 3. The attempt at a solution I believe this can be done in the same way we prove a result for reflection of light in a parabolic mirror.Please guide me if I am wrong.