PHYSICS HELP - A ball is thrown upward from the ground with

Question

A ball is thrown upward from the ground with an initial speed of 23.6 m/s; at the same instant, another ball is dropped from a building 18 m high. After how long will the balls be at the same height above the ground?

Answer 1

The ball that is dropped from 18 m will have the equation y = 18 - 4.9t2

and the ball thrown upwards will have equation y = 23.6t - 4.9t2

equating the two equations and solving for t, we find that the time where they meet in the air is

t = .763 seconds