posted by Ann .
A rubber ball is attached to a paddle by a rubber band. The ball is initially moving away from the paddle with a speed of 4.0 m/s. After 0.25 s, the ball is moving toward the paddle with a speed of 3.0 m/s. What is the average acceleration of the ball during that 0.25 s? Give the magnitiude and direction.
a = (V-Vo)/t = (-3-4)/0.25 = -28m/s^2.