An open organ pipe of length `11 cm` in its fundamental mode vibrates in resonance with the first overtone of a closed organ pipe of length `13.2 cm` filled with some gas . If the velocity of sound in air is `330 m//s`, calculate the velocity of sound in the unknown gas .

Explanation

The frequency of the fundamental mode of the open pipe filled with air
`( c )/( 2 I) = (330)/( 2 xx 0.11) = 1500 Hz`
The first overtone of the closed pipe
` = 3 xx ( c_(gas))/( 4 xx 0.132)`
`:. 3 xx ( c_(gas))/( 4 xx 0.132) = 1500 or c_(gas) = 264 m//s`