In order to determine if the ball reaches the 24 ft, replace h = 24 and solve the quadratic equation. If the solutions are real, then, the ball does reach 24ft.
Proceed as follow:
h = 16t² + 36t + 6
24 = 16t² + 36t + 6
16t² + 36t + 6 - 24 = 0
16t² + 36t - 18 = 0
use he quadratic formula, given by:
![t=\frac{-b\pm\sqrt[]{b^(2)-4ac}}{2a}](https://img.qammunity.org/2023/formulas/mathematics/high-school/8orcbdru4z1lvz6tzrhuaipyvdjw9fb1v2.png)
In this case, a = 16, b = 36 and c = -18
![\begin{gathered} t=\frac{-36\pm\sqrt[]{(36)^(2)-4(16)(-18)}}{2(16)} \\ t=(-36\pm49.47)/(32) \\ t_1=-2.67 \\ t_2=\text{0}.42 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/rgxukwiusrztzhybow23gid8t2xqqximfa.png)
negative times do not have physical meanning, then, the available solution is
t = 0.42
Hence, you can conclude that the ball reaches 24 ft for a time of 0.42 seconds.