A ball is thrown upward from the ground with an initial speed of 23.1 m/s; at the same instant, a ball is dropped from a building 15.0 m high. After how long will the balls be at the same height?

Answer 1

Find the t value that satisfies this equation:

Y1(t) = Y2(t)
23.1 t - 4.9 t^2 = 15 - 4.9t^2

23.1 t = 15
t = 0.649 s