PHYSICS · Subjective · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
A ball P is dropped from the top of a tower 80m high. Simultaneously, another ball Q is projected vertically upward from the foot of the tower with a speed of 30m s−1. Neglect air resistance and take g=9.8m s−2.
(a) Compute the time after which the two balls meet.
(b) Determine the height above the foot of the tower at which they cross each other.
(c) Calculate the magnitude of their relative velocity just before they meet.