A small smooth ball strikes a smooth vertical wall at right angles.
Its kinetic energy after impact is one-half of its initial kinetic energy.
Find the coefficient of restitution between the ball and the wall.
This is what I have got so far:
Let speed of approach be u and speed of separation be v
KE = 1/2 mv^2
1/2 m (2)^2 = 1/2 * 1/2 m (v) ^2
Then I just do not have a clue what to do from there.
If it helps the textbook tells me the answer is e = 1/√2, I just don't know how to get there...
Any help will be appreciated