In a closed organ pipe, the frequency of fundamental note is 30 Hz. A certain amount of water is now poured in the organ pipe so that the fundamental…

In a closed organ pipe, the frequency of fundamental note is $\displaystyle 30$ Hz . A certain amount of water is now poured in the organ pipe so that the fundamental frequency is increased to $\displaystyle 110$ Hz . If the organ pipe has a cross-sectional area of $\displaystyle 2 \mathrm{~cm}^2$, the amount of water poured in the organ tube is $\displaystyle \_\_\_\_$ g. (Take speed of sound in air is $\displaystyle 330 \mathrm{~m} / \mathrm{s}$ )