Question

a ball is dropped from a height of 120 meters. it takes 2 seconds for the ball to fall 60 meters, how long before the ball hits the ground?

Answer 1

The ball was dropped not thrown so vo = 0

the the gravity accelerates the ball


s = vot + 1/2 a t^2

60 = 0  + 1/2 a (2)^2 

a = 30 m/s

120 = 0 + 0.5 x 30 x t^2   (time to drop 120 meters, from inital point)

t = 2sqrt(2) = 2.83 s