A boy standing on top a building with a height of 500m throws a ball vertically upwards. The balls take 40s to reach to the ground. Neglecting the height of the boy throwing the ball, determine the velocity of the ball.

Answer 1

0 = -.5 g (40^2) + Vo(40) + 500

solve for Vo (the throwing velocity)

Vo / g is the time to max height

40 - (Vo / g) is the free fall time

(40 * g) - Vo is the impact velocity