The fundamental frequency of a closed organ pipe is equal to the first overtone of an open organ pipe. If the length of the open pipe is 60 cm, What is the length of the closed pipe?

Explanation

Fundamental frequency of a closed organ pipe,
`v_(1)=(v)/(4L)`
Fundamental frequency of an open organ pipe,
`v'_(1)=(v)/(2L')`
Frequency of first overtone of open organ pipe,
`v'_(2)=2v'_(1)(v)/(2L')`
Given `v'=v'_(2)`
`:.(v)/(4L)=(v)/(L')`
(or) `L=(L)/(4)=(60)/(4)=15cm`.