Tuning Fork Beats


A lump of Blu-Tack changes the frequency of a tuning fork
A lump of Blu-Tack changes the
frequency of a tuning fork

Two tuning forks with slightly different frequencies give beats.



Principles Illustrated

The addition of a small lump of Blu-Tack to a tuning fork changes its frequency. When struck along with a matching fork that has no Blu-Tack, beats result.

NCEA & Science Curriculum

PHYS 3.3, PHYS 3.4


The forks in the photo above nominally produce 256 Hz. The addition of the Blu-Tack results in beats at a few Hz. You can adjust the increase the beat frequency by adding a larger lump of Blu-Tack. The forks have to be held near the head.


Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.

Related Resources

Beats from speakers || Combining Sounds

Teaching Resources

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Related to PIRA 3B60.10


This teaching resource was developed with support from

The MacDiarmid Institute
Faculty of Science, Victoria University of Wellington
School of Chemical and Physical Sciences, Victoria University of Wellington


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