Question

A local football player is practicing football on top of a 35 m high hill. he kicks the soccer ball, which lands 50 m from the base of the hill. determine the initial horizontal velocity of the soccer ball.

Answer 1

The range of projectile

$$L=v_0\sqrt{2H/g}$$

Hence, the initial velocity

$$v_0=\frac{L}{\sqrt{2H/g}}=\frac{50}{\sqrt{2*35/9.8}}=18.7\:\rm m/s$$