A 57.0 g tennis ball with an initial speed of 25.2 m/s hits a wall and rebounds with the same speed. The figure below shows the force of the wall on the ball during the collision. What is the value of Fmax, the maximum value of the contact force during the collision, if the force is applied for ti=34.8 milliseconds? I've tried using the formula Force = change in momentum/change in time; after determining change in momentum with m1v1=m2v2. p1 =m1v1 =(0.057kg)(25.2m/s) =1.4364 kgm/s p2 =m2v2 =(0.057kg)(-25.2m/s) =-1.4364kgm/s Change in p = -2.8728kgm/s F = 2.8728kgm/s/0.0348s = -82.55N However, this is not the answer. Any help would be appreciated.