1. The problem statement, all variables and given/known data A baseball pitcher throws a ball vertically upward and catches it at the same level 4.2s later a) with what velocity did the pitcher throw the ball? 2. Relevant equations 3. The attempt at a solution I put this into givens t = 4.2 s displacement = 0 m if the ball goes up and then comes back at the same level I figured it has a displacement of 0 acceleration = -9.81 m/s Vf = 0 m/s since it goes up then reaches a climax and it was already thrown with an initial velocity that you are trying to find so I decided to use the vf = vi + a(t) so.. then I rearranged it so that it was vf - ( a ) ( t ) = vi which gave me -(-9.81)(4.2) = vi and then I got 41.2 but thats not the right answer :S so im not sure if its just that im using a wrong equation or that I have the wrong givens I don't know exactly what im doing wrong please point me in the right direction.