Question

Derive the frequency for a third harmonic in a closed pipe from `f=v/lamda` ?

Answer 1

`f= (3v)/(4L)`

Explanation:

Well let's see, we know that frequency is equal to:
`f=v/lamda`

We also know that the wavelength at a third harmonic in a closed pipe is:
`L=3/4lamda`

`L` is the length of the pipe

Isolate lamda:
`4/3L= lamda`

Substitute for wavelength in the first equation:
`f=v/(4/3L)`

`f= (3v)/(4L)`