1. The problem statement, all variables and given/known data A pen falls from the top of a roof. We know that it takes 1.5 seconds to fall the last 1/4 distance. Find the height of the roof from the ground. 2. Relevant equations x=x_0 + v_0 * t + 1/2 gt^2 v=v_0 + gt 3. The attempt at a solution Since the problem does not say that the pen falls from rest, I don't know what v_0 should be. Also, how can I make use of the time that it travels the last 1/4 distance. Any help please.