Question

A criminal is escaping across a rooftop and runs off the roof horizontally at a speed of 6.8 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 1.1 m below the jumping-off point. Find the maximum value for D. (g = 9.80 m/s2)

Answer 1

3.223 m

Step-by-step explanation:

u = 6.8 m/s

h = 1.1 m

g = 9.9 m/s^2

Let it takes time t to jump from one building to another.

use second equation of motion in vertical direction.

h = u t + 1/2 g t^2

in the vertical direction, u = 0

h = 1/2 g t^2

1.1 = 0.5 x 9.8 x t^2

t = 0.474 second

Use second equation of motion in horizontal direction.

S = u t + 1/2 a t^2

In horizontal direction, a = 0

So,

D = u t = 6.8 x 0.474 = 3.223 m