Physics question

Question

How would I solve for this?

A ball is thrown horizontally from the top of a 51.5 m building and lands 107.3 m from the base of the building. Ignore air resistance. What must have been the initial horizontal component of the velocity? Indicate the direction with the sign of your answer.

Answer 1

The speed is constant in the horizontal direction. The ball travels 107.3 m in the horizontal direction in the same time it drops 51.5 m in the vertical direction.

h = gt² / 2 ⇒

t = √(2h/g)

d = vt ⇒

v = d/t = d / √(2h/g)

Plug in these numbers and get v in m/s:

d = 107.3 m

h = 51.5 m

g = 9.8 m/s²