During softball practice, a softball pitcher throws a ball whose height can be modeled by the equation h = -16t^2 (<--squared) + 24t + 1, where h=height in feet and t = time in seconds. How long does it take for the ball to reach a height of 6 feet?

Answer 1

just plug in the numbers:

6 = -16t^2 + 24t + 1
16t^2 - 24t + 5 = 0
(4t-1)(4t-5) = 0

t = 1/4 (ball rising)
t = 5/4 (ball falling)

Answer 2

0.25 secs,1.25 secs

Given, height = 6 = -16
t
2
+ 24t + 1

⇒
16
t
2
+ 24t + 5 = 0

⇒
(4t-1) (4t-5) = 0

t =
1
4
,
5
4
or 0.25,1.25

It takes 0.25 secs and 1.25secs for the ball to go up and down respectively.