what is the acceleration of ball if a ball throw to the wall with velocity of 6m/s and after striking the wall it backs with velocity of 4.4m/s the time for which ball strike the wall is 0.04seconds.

change in velocity ... -4.4 m/s - 6 m/s = -10.4 m/s

acceleration = -10.4 m/s / 0.04 s