1. The problem statement, all variables and given/known data A person standing on top of a building of height H throws a ball vertically upward with initial velocity Vj. He then throws an identical ball vertically downward with initial velocity -Vj. Compare the velocities of the two balls just before they strike the ground. Write equations to explain your reasoning. 2. Relevant equations Vf=Vi+At Yf=Yi+Vit-At^2 Acceleration=-9.8 m/s^2 Velocity at time T=4.9t^2 3. The attempt at a solution I know that at the point when the first ball gets back to y=0 the velocities are the same. I do not know how to keep comparing them to show the balls are the same just before they hit the ground. Any help is appreciated!