To determine the sound propagation velocity in air by acoustic resonance technical one can use a pipe with a piston and a sonic membrane closing one of its ends. Find the velocity of sound if the distance between the adjacent positions of the piston at which resonance is observed at a frequency `v=2000Hz` is equal to `l=8.5 cm.`

Explanation

Obviously in this cse the velocity of sound propagation
`v=2v(l_(2)-l_(1))`
where `l_(2)` and `l_(1)` are consecutive lengths at which resonance occur
In our problem, `(l_(2)-l_(1))=l`
So, `v=2 v l = 2 xx 2000 xx 8.5 cm //s =0.34 km //s`.