1. The problem statement, all variables and given/known data A golf ball released from a height of 2.02 m above a concrete floor, bounces back to a height of 0.86 m. If the ball is in contact with the floor for 3.57 ms( or .00357s), what is the magnitude of the average acceleration a of the ball while it is in contact with the floor? 2. Relevant equations Is the .86m bouncing back up irrelevant? 3. The attempt at a solution I found out that the initial position is 2.02m and the initial position is 0m and I cut the time in half and used 9.8 as my acceleration. I'm just really stuck and have gotten myself caught up in so many different equations my brain can not handle it anymore. Any help would work please.