1. The problem statement, all variables and given/known data A ball is projected vertically upwards from the top of a building that is 25 m high. After a time of 3 s it passes the edge of the building on its way down to the ground. In this question, g=10ms-2. a) What is it's initial velocity? 2. Relevant equations s=so + vot + 1/2gt2 v= vo + at 3. The attempt at a solution Basically, all I want to know is this: Does the question want me to assume that it reaches the top of the projectile 'arc' where velocity in the vertical direction is zero, when the time is 1.5 seconds (half of 3 seconds). Or is there a mathematical way of showing it? I'd be fine if I knew one more variable, but I know very few variables... Thanks in advance.