3B70.10 Coupled Tuning Forks


Coupled Resonance


A tuning fork (mounted on a resonance box) is made to resonate when a second identical tuning fork is rung nearby. This is beacause the first tuning fork's driving frequncy is the same as the second tuning fork's natural frequency.



  • [2] Identical tuning forks mounted on resonance boxes
  • [1] Rubber mallet

Classroom Assembly

  1. Place the rubber mallet and tuning forks on the lectern with the open ends of the resonance boxes facing each other.

Important Notes

  • Details of the tuning forks can't be seen in a large lecture hall, but the sound can be clearly heard.


  1. Place the tuning forks so the openings of the resonance boxes are a few inches apart.
  2. Hit one tuning fork with the rubber mallet.
  3. Damp the same tuning fork by holding onto the tines. Note that the second tuning fork (which was not hit) is rining.

Additional Resources


  • PIRA 3B70.10

Last revised

  • 2018


Related AV

Related demos

If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.