Question

A criminal is escaping across a rooftop and runs off the roof horizontally at a speed of 4.2 m/s, hoping to land on the roof of an adjacent bullding Air resistance is negligible. The horlzontal distance between the two buildings is D, and the roof of the adjacent building is 2.1 m below the jumping off polint Find the maximum value for D. (g 9.80ms

Answer 1

Answer:

Maximum separation between buildings, D = 1.806 m

Explanation:

Vertical motion of criminal

Initial speed = 0 m/s

Acceleration = 9.81 m/s²

Displacement = 2.1 m

We need to find time when he moves vertically 2.1 m.

We have

         s = ut + 0.5at²

        2.1 = 0 x t + 0.5 x 9.81 x t²

           t = 0.43 s.

Horizontal motion of criminal

Initial speed = 4.2 m/s

Acceleration =0 m/s²

Time = 0.43 s

We need to find displacement.

We have

         s = ut + 0.5at²

        s = 4.2 x 0.43 + 0.5 x 0 x 0.43²

       s = 1.806 m

So maximum separation between buildings, D = 1.806 m