An air column enclosed in an open pipe is vibrating in its fundamental mode . The fundamental frequency is 30 Hz. If the velocity of sound air is `300 m s ^(-1)` , find the length of the pipe and frequency of 3rd overtone .

Explanation

Fundamental frequency of an open pipe = `(v)/(2l)`
`implies 30 Hz = (300 m s^(-1))/(2l)`
`implies l = (300)/(2 xx 30) = 5` m
Frequency of third overtone = `4 xx n = 4 xx 30 = 120` Hz