Answer
(a) equal to
(b) II
Work Step by Step
(a) We know that the time of flight of the coin is the same whether it is flipped on the ground or in the elevator moving with constant speed.
(b) We know that the best explanation is option (II) -- that is, 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.
