Which expression is equivalent to b^-2/ab^-3 assume a=0 b=0 answers: a/b^5 1/ab^5 a^3b/1 b/a

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-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.) t =