Question

If a 1.5 m long tube with a 0.5 cm opening has its first resonance point at 37 cm, what would be the theoretical location of L3 (in meters with 2 decimal places)? Is it possible to hear the third resonance point in the tube?

Answer 1

Given data l=1.5 m

1 m=100 cm

Here 1.5 m is given we have to convert to meters

So, 1.5 m*100=150 cm

Here from data length of first resonance L _{1=37 cm}

If it is a closed pipe then

    L ₁: L ₂:L ₃=1:3:5:7:--------

L ₃=5 L ₁

=5(37)

L 3=185 cm

Here we got 185>150

:It is a closed pipe we can’t hear the third resonance

For open pipe L ₁:L ₂:L _3:=====1:2:3

L ₃=3 L ₁

    =3(37)

   =111 cm (111<150)

:Here we can listen the third resonance

i.e., L 3=111 cm