Question

The boy on the tower of height h = 16 m in the figure below throws a ball a distance of x = 64 m, as shown. At what speed, in m/s, is the ball thrown?

Answer 1

So if the time to hit the ground is
y=1/2*g*t^2 (projectile formula)

then
t=sqrt(2*y/g) = sqrt(2*16/9.8) = 3.26s

so then
64m/3.26s = 19.63m/s