A whistle of frequency 500 Hz tied to the end of a string of length...

{v}_{s} = r\omega = 1 . 2 \times 2\pif~ & \left[∵ \omega = 2\pif\right]

$= 1 . 2 \times 2 \times 3 . 14 \times \left(\dfrac{400}{60}\right) = 50ms^{- 1}$

{v}_\min = \dfrac{v}{v + {v}_{s}} \cdot v

$= \dfrac{340}{340 + 50} \times 500$

$= 436Hz$

{v}_\max = \dfrac{v}{v - {v}_{s}} \cdot v

$= \dfrac{340}{340 - 50} \times 500$

$= 586Hz$