I'm not entirely sure of my answer, if it's wrong could some one point me in the right direction? 1. The problem statement, all variables and given/known data A 140g ball is falling through the air at 36 meters per second (constant speed) prior to time 0. The ball impacts the floor at time 0. The ball decelerates until time 0.012. At this time ball has come to rest. Between time 0 and time 0.012 what is the rate of deceleration? Then using this data calculate the magnitude of the force exerted by the floor. 2. Relevant equations Deceleration = initial speed minus final speed divided by time. 36 m s-1 - 0 m s-1 / 0.012 s = 3000 m s -1 Calculate the magnitude of the unbalanced force exerted by the floor. F = ma F = 140g x 36 m s-1 = 5040 newtons. OR IS IT F = 140g x 3000 m s-1 = 420,000 newtons. 3. The attempt at a solution The solution would be 5040 newtons was being exerted by the floor. But is this correct? I under stand that acceleration is a CHANGE in velocity with in time. If the speed is constant until there is no acceleration only deceleration after the impact?