Ball A is dropped from rest from the top of a cliff 80m high at the same instant that ball B is projected vertically upward from the foot of the cliff with a speed of 30ms−1. Neglect air resistance.
(i) Determine the time after release when the two balls pass each other.
(ii) Calculate the height above the ground where the balls meet.
(iii) Find the magnitude of the velocity of each ball at the instant of passing and hence compute their relative speed.