1. The problem statement, all variables and given/known data A ball bounces on the floor with elastic collisions like in the drawing. The collisions take a short time in comparison to the travel between the collisions. What is the direction of the acceleration at point B? Why is the magnitude of the acceleration at point B bigger than at point A? 2. Relevant equations In elastic collision with the floor the rebound velocity is the same as the approach velocity and energy is conserved. 3. The attempt at a solution Because the ball travels to the right with identical loops the horizontal velocity is conserved so only the vertical component of the hit velocity changes direction, so the acceleration is directed upwards. The ball has to acquire vertical velocity and just because it is said the time for the collisions is short i can assume the acceleration is higher than g, which is at point A, but i feel this explanation isn't good.