4.

a)
We need to find the roots of the equation, so:

Solve for t using quadratic formula:
![\begin{gathered} t=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ _{\text{ }}where\colon \\ a=-1 \\ b=32 \\ c=48 \\ so\colon \\ t=\frac{-32\pm\sqrt[]{1024+192}}{-2} \\ so\colon \\ t1=\frac{-32+8\sqrt[]{19}}{-2} \\ t2=\frac{-32-8\sqrt[]{19}}{-2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/jqjw6qnonhnzwuclaprfhi785n4k3c4lvw.png)
So, the total time T is:

Answer:
33.436 s
b)
We need to evaluate the function for t = 1:

Answer:
79ft
c)
The initial height is the height of the ball for t = 0, so:

Answer:
48ft