Answer
$f = 86~Hz$
A person with a hearing range of $60~Hz$ to $20~kHz$ would be able to hear the fundamental mode.
Since $86~Hz$ is quite close to $60~Hz$, which is the bottom of the range, the sound would be low frequency.
Work Step by Step
We can find the fundamental frequency:
$f = \frac{nv}{2L}$, where $n = 1$
$f = \frac{(1)(343~m/s)}{(2)(2.0~m)}$
$f = 86~Hz$
A person with a hearing range of $60~Hz$ to $20~kHz$ would be able to hear the fundamental mode.
Since $86~Hz$ is quite close to $60~Hz$, which is the bottom of the range, the sound would be low frequency.
