Answer
\[
24 \mathrm{ft} / \mathrm{s}
\]
Work Step by Step
\[
\begin{array}{l}
s(t)=s_{0}+v_{0} t-\frac{g}{2} t^{2} \\
v(t)=v_{0} -g t\\
g=32 \mathrm{ft} / \mathrm{s}^{2}
\end{array}
\]
Using Formula (15) and Formula (16) from the book:
$0=s(t)=112-v_{0} \cdot 2-4 \cdot 16$
$\Rightarrow -48= -2 v_{0}$
$\Rightarrow -24=-v_{0} \\ v_0 = 24 ft/s $
