Question

A ball is thrown horizontally from the top of a 43 m vertical cliff and lands 85 m from the base of the cliff. How long is the ball in motion?

Answer 1

Sx = Vx0 t + 1/2 ax t^2 horizontal distance ball travels

Vy = Vyo + g t vertical speed of ball

Sy = 1/2 g t^2 (the vertical speed Vy0 is zero at t = 0)

t = (2 Sy / 9.80)^1/2 = (2 * 43 m / 9.8 m/s^2) = 2.96 sec