A ball is thrown vertically upward from the top edge of a 25m high tower with an initial speed of 15ms−1. Neglect air resistance and take g=9.8ms−2 downward.
(i) How high above the top of the tower does the ball rise before coming to momentary rest?
(ii) How long after being thrown does the ball reach the ground at the foot of the tower?
(iii) What is the magnitude of its velocity just before it strikes the ground?