Answer:
length of the shortest open-open tube 8.6 m
length of the shortest open-closed tube 4.3 m
Explanation:
Fundamental frequency for standing wave mode of an open- open tube is given by
[tex]f_{1} =\frac{v}{2L}[/tex]
where v is the velocity of the air ,v=343 m/s and L is the length
The length of open-open tube needed is
[tex]f_{1} =\frac{v}{2L} \\L=\frac{v}{2f_{1}} \\L=\frac{343}{2\times 20} \\L=8.6 m[/tex]
Fundamental frequency for standing wave mode of an open- close tube is is given by
[tex]f_{1} =\frac{v}{4L}[/tex]
The length of open-close tube needed is
[tex]L=\frac{v}{4f_{1}} \\L=\frac{343}{4\times 20} \\L=4.3m[/tex]
