#### Answer

$L=0.81$ ft

#### Work Step by Step

To find the length of the pendulum, we need to substitute the value of period $P=1$ sec in the formula and solve:
$P=2\pi\sqrt {\frac{L}{32}}$
$1=2\pi\sqrt {\frac{L}{32}}$
$\frac{1}{2\pi}=\sqrt {\frac{L}{32}}$
$\frac{1}{4\pi^{2}}= {\frac{L}{32}}$
$\frac{32}{4\pi^{2}}= L$
$L=0.81$ ft