Question

A ball is thrown from a height of 140 feet with an initial downward velocity of 8 ft/s. The ball's height (in feet) after seconds is given by the following. h= 140 - 8t - 16t^2 How long after the ball is thrown does it hit the ground? Round your answer(s) to the nearest hundredth.

Answer 1

when it hits the ground h(t) = 0 so:-

140 - 8t - 16t^2 = 0

4t^2 +2t - 35 = 0

t = 2.72 answer