1. The problem statement, all variables and given/known data A ball is thrown upward from a building 30 meters tall and misses the edge on its way down, hitting the ground 6 seconds after it was thrown. A) With what speed was it thrown? B) What is its highest height? 2. Relevant equations Vf = Vi + at x = 1/2(Vi + Vf) x = Vi t + 1/2(at^2) Vf^2 = Vi^2 + 2ax Vf = final velocity Vi = initial velocity a = acceleration x = distance t = time 3. The attempt at a solution So, it is a two part problem, the upward motion, and then the downward. I will label the distance from being thrown to the highest point of the arc as x1, which is also the same distance down to being level with where it was thrown from, and then x2 is 30 meters. Thus goes that to find time, I need to use x = Vi t + 1/2(at^2). xtotal = x1+30 Vi = 0 t2 = 6 - t1 a = 10 (lets make positive downward) So here I am stumped by the fact that I do not have three known variable to make use of the equation. How am I supposed to proceed?