Question

from the top of a building 19. 6 metre high A ball is projected horizontally after how long does it strike the ground is the line joining the point of projection to the point where hits the ground makes an angle of 45 degree with the horizontal what is initial velocity of the ball

Answer 1

Range R is covered by the horizontal component of velocity that is initial velocity, because ball is projected horizontally.

So distance=speed×time
R=u×t
19.6=2u
u=9.8m/s