Question

Two pipes simultaneously vibrate with their fundamental frequencies, one at 400 Hz and another at 800 Hz. Each pipe can be either an open-open or an open-closed pipe. Assume that the speed of sound in air is 340 m/s. Determine the length of the pipes if you know that the pipes have equal lengths.

Answer 1

Answer:

Explanation:

Given

Two Fundamental frequencies are 400 Hz and 800 Hz

Each Pipe has same length L

Fundamental frequency corresponding to pipe with both side open

$f_0_{opn}=\frac{v}{2L}$

where v=velocity of sound

Fundamental frequency corresponding to pipe with one side open and other side close

$f_0_{close}=\frac{v}{4L}$

we can see that fundamental frequency of both side open pipe is twice of second pipe

so 800 Hz frequency will correspond to both side open pipe

$800=\frac{340}{2\cdot L}$

$L=0.2125\ m$