Explanation

(c) For an open pipe of length l, the frequency v is given by
$v = v^{''}.\frac{v}{2l}$
Where v is velocity of sound, v’ the overtone.
Given, v=450 Hz, 𝒍=1m,
$v = 330\ ms^{- 1}$
$v^{''} = \frac{v(2l)}{v}$
$= \frac{480 \times 2 \times 1}{330} = 2.3 \approx 3$
[image:15_image86.emf]
Hence, this is the second overtone or third harmonic.