A ball is thrown upwards from a height of 16ms-1 from the edge of a cliff 144m above sea level.
(Acceleration down wards = 9.8ms-2)
The displacement of the sea from the top of the cliff = -144m
Given that the displacement of the ball from the cliff top x seconds after it is throw upwards is x = 4.9x2 - 16x, prove that it will take 7.294 seconds for the ball to hit the sea.
+37146 4.9x^2 - 16x = 144
4.9x^2 - 16x - 144 = 0 use quadratic formula a = 4.9 b= -16 c = - 144 x = 7.294 s or - 4.029 ( throw out)
