What is the initial velocity of the ball:
A ball is horizontally thrown from the top of a building 60 m height, hits the horizontal ground 25 m from the base of the building a. What is the initial velocity of the ball?
Let the top of the building corner be the origin. So
vx = v and v y = 0
- 60 = - (½) g t 2
∴ t = 3.5 seconds
x = v t
v = x/t = 25 = 7.143 m / sec.