Aball is thrown horizontally from a platform so that the initial height of the ball is 6.0 m above the level ground below. the ball lands 24 m from its original horizontal location. find how fast the ball was thrown. show all work.

We can first obtain time of flight from vertical fall
Initial velocity U=0, d = 6 m, a = 9.8 m/s² 
d = ut + 1/2 at²
6.0 = 0 + (1/2 × 9.80 t²) 
t = √(12/9.8)
 = 1.106 sec
Horizontal velocity = Vh = Dh/t
  = 24.0 /1.106 s
  = 21.69 m/s
The ball was thrown at a speed of 21.69 m/s