Answer
$3.51$ seconds
Work Step by Step
Given \begin{equation}
T(L)=2 \pi \sqrt{\frac{L}{32}}.
\end{equation} We know that $L = 10$ feet. Substitute this into the formula to find the period of the pendulum. \begin{equation}
\begin{aligned}
T(3) & =2 \pi \sqrt{\frac{10}{32}} \\
& \approx 2 \pi\cdot (0.55901) \\
& \approx 3.512.
\end{aligned}
\end{equation} The period of a pendulum with length of $10$ feet is about $3.51$ seconds.
