Find the frequency of the third overtone of an air column vibrating in a pipe closed at one end. The length of the pipe is 30cm and the innter diameter of the pipe is 2 cm the speed of sound in air at room temperature is 350 m/s .

Explanation

Data : L = 30 cm = 0.3 m v = 350 m/s , d= 2 cm ` 2 xx 10^(-2)` m
Pipe closed at one end
Fundamental frequency ` n= v/(4 (L+ 0.3d))`
The frequency of the third overtone = 7n
` = (7v)/(4(L + 0.3d)) = ( 7 xx 350)/( 4 (0.3 + 0.3 xx 2 xx 10^(-2))`
` = ( 7 xx 175)/(2(0.3 + 0.006)) = (7 xx 175)/( 2 xx 0.306)`
2002 Hz