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.
x=x_0 + v_0 * t + 1/2 gt^2
v=v_0 + gt
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.