Hints

1. Choose a specific time interval in the animation, that is, specific starting and stopping times.
2. Read the ball's velocity at the starting time and again at the stopping time.
3. Divide the change in velocity by the time it takes to undergo that change.
4. Does it make any difference whether you study the ball on the way down or the way up?
5. How does gravity on this planet compare to Earth's gravity?

Reference

See Walker, Section 2-7

Illustration written by Steve Mellema