As you walk briskly down the street, you toss a small ball into the air.
(a) If you want the ball to land in your hand when it comes back down, should you toss the ball straight upward, in a forward direction, or in a backward direction, relative to your body?
(b) Choose the best explanation from among the following:
I. If the ball is thrown straight up you will leave it behind.
II. You have to throw the ball in the direction you are walking.
III. The ball moves in the forward direction with your walking speed at all times.