Question

A closed organ pipe can vibrate at a minimum frequency of 500 Hz. Find the length of the tube. Speed of sound in air = 340 m s⁻¹.

Answer 1

Given:
Speed of sound in air v = 340 ms⁻¹
Frequency of closed organ pipe f = 500 Hz
Length of tube L = ?
Fundamental frequency of closed organ pipe is given by:
$f=\frac{v}{4L}$
$$\begin{gathered} \therefore L=\frac{v}{4f} \\ \therefore L=\frac{340}{4\times 500}=0.17\mathrm{m}=17\mathrm{cm} \end{gathered}$$