At time t=0, a ball is thrown downward at 24 feet per second from a height of \(180\) feet above the ground. The equation $h = -16t^2 - 24t +180$ describes the height (in feet) of the ball. In how many seconds will the ball hit the ground? Express your answer as a decimal.
When the ball hits the ground , h = 0
0 = -16t^2 - 24 t + 180
Use Quadratic Formula with a = -16 b = -24 c = 180
\(t = {-(-24) \pm \sqrt{(-24)^2-4(-16)(180)} \over 2(-16)}\)
to calculate 't' (Hint: it is NOT 3.6 sec ) ==== throw out the negative 't' value