Answer
$2.5$ seconds
Work Step by Step
Given \begin{equation}
t=\sqrt{\frac{2 h}{32}}.
\end{equation} We are given that $h = 100$ feet and want to find the time that an object falls below $100$ feet. Find $t(100)$. \begin{equation}
\begin{aligned}
t(100) & = \sqrt{\frac{2\cdot 100}{32}} \\
&=2.5.
\end{aligned}
\end{equation} It will take $2.5$ seconds for an object to fall $100$ feet below.
