1. The problem statement, all variables and given/known data A ball is thrown vertically upward with an initial velocity at the edge of the roof of a building which is 30m above the ground. The speed of the ball is 14.5 m/s when the ball is 12m above the ground. How long does the ball take to reach maximum height? 2. Relevant equations Vf^2=Vo^2+2ad 3. The attempt at a solution First, i use that equation to find distance between the highest point and 12 above ground. Then I plan to use it one more time to find the initial velocity. But the thing is that I find d=-10.727m as the distance between highest point and 12 above ground. This doesn't make sense, shouldn't it be higher than 18m?