Aball is thrown from a height of 140 feet with an initial downward velocity of 8 ft/s. the ball's height h (in feet) after t 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.
(if there is more than one answer, use the "or" button.)