To determine the sound propagation velocity in air by acoustic resonance technique 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 \(v=2000 \mathrm{~Hz}\) is equal to \(l=\) \(=8.5 \mathrm{~cm}\)