3B80.10 • Resonance Tube

Location: Cabinet 6

Instructions:

• Ensure that the nail support is not fixed to the post.
• Tie the string to the mass, and lower the mass into the tube.
• Strike the tuning fork and hold it at the lower end of the tube.
• The mass acts as a closed end for the tube, so the length of the tube can be adjusted by changing the height of the mass. At specific lengths of the tube, resonance will occur for the chosen frequency. The length of the tube is measured starting from the bottom.
• It is easiest to make out the resonance when oscillating around the given height.

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Concepts Conveyed:

• Fundamental frequencies; Constructive interference occurs at every quarter wavelength of the sound wave (this can be observed by an increase in amplitude of the sound) when the wave is reflected from the closed end of the tube.

Picture shows demonstration used at the University of Texas at Austin

Last updated on April 27, 2026