In an open organ pipe ν_3 and ν_6 are 3^rd and 6^th harmonic frequencies, respectively. If ν_6-ν_3=2200 Hz then length of the pipe is ____ mm. (Take…

In an open organ pipe $\displaystyle \nu_3$ and $\displaystyle \nu_6$ are $\displaystyle 3^{\text {rd }}$ and $\displaystyle 6^{\text {th }}$ harmonic frequencies, respectively. If $\displaystyle \nu_6-\nu_3=2200 \mathrm{~Hz}$ then length of the pipe is $\displaystyle \_\_\_\_$ mm . (Take velocity of sound in air is $\displaystyle 330 \mathrm{~m} / \mathrm{s}$.)