A simple pendulum is constructed using a $3\mathrm{.}9$ kg bob fastened to the end of a $1\mathrm{.}7$ m string.

Which equation would be most useful for finding the period of the pendulum?

$T=2\sqrt[\phantom{2}]{\frac{m}{k}}$

$T=2\sqrt[\phantom{2}]{\frac{L}{g}}$

$T=\frac{1}{f}$

$v=\sqrt[\phantom{2}]{\frac{T}{\frac{m}{L}}}$