Answer
1.6 seconds
Work Step by Step
We find:
$T = \frac{2\pi}{\omega}=2\pi \times \sqrt{\frac{I}{mgL}} = 2\pi \times \sqrt{\frac{\frac{1}{3}m(2L^2)}{mgL}} = 2\pi \times \sqrt{\frac{4L}{3g}}$
Plugging in the values gives an answer of $\fbox{1.6 seconds}.$
