Question

A pipe closed at one end is sounding its fundamental note. If the length of the pipe is 10cm, calculate the wavelength of the note. (neglect end correction of the pipe).

Answer 1

The fundamental frequency (with $n = 1$ ) in a pipe closed at one end is given by the following expression:

$$f = \dfrac{nv}{4L} = \dfrac{v}{4L}$$

where $v$ is the speed of sound in air, $L = 10cm = 0.1m$ is the length of the pipe. The wavelength will be:

$$\lambda = \dfrac{v}{f} = 4L = 4\cdot 0.1m = 0.4m$$

Answer. 0.4 m.