A ball is thrown straight up at an initial speed of 9.8m/s and, on returning to your hand, hits it moving downward at the same speed. If the whole trip took 2.0s, determine the ball's (a) average acceleration and (b) average velocity.

-9.8 m/s²

0 m/s

Explanation:

Average acceleration is the change in velocity over change in time.

a = Δv / Δt

a = (-9.8 m/s - 9.8 m/s) / 2.0 s

a = - 9.8 m/s²

Average velocity is the change in position over change in time.

v = Δx / Δt

v = (0 m - 0 m) / 2.0 s

v = 0 m/s