1. A ball is launched against a solid wall with straight trajectory and a velocity of Vo. It hits the wall on a 3ft height and it falls on the ground at a 2ft distance (by the left of the wall). Then, an elastic platform is positioned on the exact height of the collision of the ball, and it is throwed once again, with the same velocity. But now, it falls on the ground at a distance of 0,83ft. a) Coefficient of restitution = ? b) Vo = ? g = 32,17; No drag; My attempt was to calculate the velocity right after the wall colision, and right after the platform colision, using kinematics equations for velocity (free fall and horizontal movement), and then divided both to find the coefficient, but that doesn't sound right to me. And I have no idea on how to calculate the Vo.