1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Sound propagating in air inside a tube

  1. Jun 23, 2008 #1
    Hi all.

    my question is about the implantation of an harmonic mode inside a tube closed at one end and opened at the other. A mono frequency source of sound is directed to the opened end of the tube. Inside the tube, besides air there is a soft powder. As the correct frequency is found, the powder starts shaking in a way that is in accordance with the shape of the first harmonic of this kind of tube. Nevertheless, there is also a much smaller but appearant patern in the powder. It is called striae and reflects a sort of interference patern inside the tube, as the powder gets concetrated in positions in a periodic way. If the first harmonic frequency is for instance 330 Hz the spacing between two of the successive portions where the powder concentrates lead to the frequency of 33000 Hz which is perhaps an harmonic of order 10 or something.

    This system is also known as Kundt Tube.

    I would appreciate any contribution in the direction of providing an explanation to this phenomena.

    Best wishes

  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted