A ball is shot directly upward from the ground with an initial speed of v0 = 7.80 m/s. Simultaneously, a construction elevator cab begins to move upward from the ground with a constant speed vc = 2.00 m/s. (a) What maximum height does the ball reach relative to the ground? (b) What maximum height does the ball reach relative to the floor of the elevator cab? (c) At what rate does the speed of the ball change relative to the ground (sign and magnitude)? (d) At what rate does the speed of the ball change relative to the cab floor (sign and magnitude)?