Question

13.Two balls are thrown simultaneously,͛ A ͚vertically upwards with a speed of 20m/s from
the ground, and͛ B͛ vertically downwards from a height of 40 m with the same speed and
along the same line of motion. At what points do the two balls collide ?

Answer 1

For ball A,
H = 20*t - 10*t*t ...... (1)
For ball B,
40-H= 20*t + 10*t*t ...... (2)
Adding 1 and 2
40 = 40t
t = 1
Substituting value of t in eq (1)
H = 20*1 - 10*1*1
H = 10 m
For ball B
Displacement = 40 - 10 = 30