1. The problem statement, all variables and given/known data Jim stands with a ball at the rear of a diving board, 10 m above the surface of a swimming pool. His friend Bob is swimming below, at a horizontal distance of 6 m from the front of the board. Jim thinks it would be funny to roll his ball along the diving board so that it drops on Bob’s head. Assuming that the effects of friction and air resistance are negligible, calculate the speed (in m s-1) at which Jim must roll the ball. 2. Relevant equations s=u+1/2at^2 speed=distance/time 3. The attempt at a solution rearranged s=u+1/2at^2 to find t t=1.1s speed 6/1.1=5.45m/s However the answer is 4.20m/s where did I go wrong?