Solving for Ball Collision: A vs. B Atop a Building

[kidia]

Does anyone can help me on this please?
Ball A is dropped from the top of building at the same instant the ball B is thrown vertically upward from the ground.When the balls collide,they are moving in the same direction,and the speed of A is 4 times that of B.At what fraction of the height of the building does collision occurs?
I will appreciate.

 

[Hyperreality]

So, where did you get stuck? Please show us your working so we can help you.

 

[Jameson]

Think of ways to express the paths of both balls. Maybe a kinematic equation could help or perhaps the useful K.E. equation... $$K.E. = \frac{1}{2}mv^2$$

That should get you started.

Jameson