physics
posted by chelsea .
A criminal is escaping across a rooftop and runs off the roof horizontally at a speed of 5.1 m/s, hoping to land on the roof of an adjacent building. Air resistance is negligible. The horizontal distance between the two buildings is D, and the roof of the adjacent building is 2.0 m below the jumpingoff point. Find the maximum value for D.

h = Vo*t + 0.5a*t^2 = 2 m.
0 + 4.9t^2 = 2,
t^2 = 0.408,
Tf = 0.639 s. = Fall time.
Xo = 5.1 m/s = Initial Hor. velocity
D = Xo * Tf = 5.1m/s * 0.639s = 3.26 m.