Question

A diver dives from a 9-foot-high platform with an initial speed of 16 feet per second. The height, h, of the diver can be modeled by the equation ℎ = −16^2 − 16 + 9, where t represents time in seconds. How long will it be before the diver hits the water?

Answer 1

h = -16t^2 -16t + 9

diver hits the water then h= 0
-16t^2 - 16t + 9 = 0
16t^2 + 16t - 9 = 0
t =
`(-16 + - √(16^2 - 4(16)(-9)) )/(2(16))`
t = 0.40125 or t = - 1.40125
negative cannot be the time
so, t = 0.40125 is the answer