Question

Two tall buildings face each other and are at a distance of 180 m from each other. With what velocity must a ball be thrown horizontally from a window 55m above the ground in one building ,so that enters ,a window 10.9 m above the ground in the second building.

Answer 1

Height = h= 55-10.9 
= 44.1
Distance= s= 180 m
time taken = t
so, h=1/2 gt²
or t= √2h/g
√2 x 44.1/9.8
=√88.2/9.8
=√9 = 3
 
S= velocity x t
180= velocity x 3
velocity =180/3 = 60 m/s

Answer 2

This is the solution..

Hope it helps..