3B30.45 - Trumpet and Bubbles

Code Number:
Demo Title:
Trumpet and Bubbles
Propagation of Sound Through a Medium
Area of Study:
Trumpet, Soap Bubbles.

Place the bell of the trumpet into the soap solution so that a film of bubble solution is formed on the end of the bell.  Play the trumpet and observe that the bubble is expanding slowly and trapping the air coming through the horn.  However, the sound from the trumpet is unimpeded showing that it is not the air movement though the horn that is making the sound but rather the vibrations and resonance's you are making in the horn with your lips that produce the sound.

  • Morris G. Hults, "Sound Waves", TPT, Vol. 18, # 9, Dec. 1980, p. 671, reprinted in TPT, Vol. 39, # 6, Sept. 2001, p. 377.
  • Morris G. Hults, "Sound Waves", TPT, Vol. 38, #6, Sept. 2001, p. 377, also A Potpourri of Physics Teaching Ideas - Sound, p.248
  • Borislaw Bilash II, David Maiullo, "Play That Funky Sound", A Demo a Day: A Year of Physics Demonstrations, p. 206.
  • Borislaw Bilash II, “Sound is Compressing“, A Demo A Day – A Year of Physical Science Demonstrations, p. 306.

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