A person flips a coin into the air and it lands on the ground a few feet away.
(a) If the person were to perform an identical coin flip on an elevator rising with constant speed, would the coin's time of flight be greater than, less than, or equal to its time of flight when the person was at rest?
(b) Choose the best explanation from among the following:
I. The floor of the elevator is moving upward, and hence it catches up with the coin in mid flight.
II. The coin has the same upward speed as the elevator when it is tossed, and the elevator's speed doesn't change during the coin's flight.
III. The coin starts off with a greater upward speed because of the elevator, and hence it reaches a greater height.