Answer:
476.387 Hz
714.583 Hz
Explanation:
L = Length of tube
v = Speed of sound in air = 343 m/s
Frequency for a closed tube is given by
[tex]f=\dfrac{v}{4L}\\\Rightarrow f=\dfrac{343}{4\times 0.18}\\\Rightarrow f=476.389\ Hz[/tex]
The frequency is 476.387 Hz
If it was one third full [tex]L=0.18-\dfrac{1}{3}0.18[/tex]
[tex]f=\dfrac{v}{4L}\\\Rightarrow f=\dfrac{343}{4\times (0.18-\dfrac{1}{3}0.18)}\\\Rightarrow f=714.583\ Hz[/tex]
The frequency is 714.583 Hz