Tuning fork – source of pure tones
Image
Photo:
Musical instruments are tuned with the help of the especially pure tones of a tuning fork. But why does a tuning fork produce such pure tones?
English, Spanish (CREA), German
2018-02-01
This medium is made available under a CC BY-SA 4.0 international license.
What does this mean?
How to reference this medium
With the help of a tuning fork it can be demonstrated that audible tones are often created by vibrating objects and that the tones depend on shape and dimensions of the objects. With a tuning fork all vibrations of undesired frequency are greatly attenuated or extinguished altogether. In the end only the tone which corresponds to the self-resonant frequency of the tuning fork remains. The tone is almost ideally monofrequent pure.
Information and ideas:
To check that this assumption is correct, the following experiment can be carried out:
A piece of glass covered in soot is placed on an overhead projector. A tuning fork is struck and the point of one of the tines is put carefully on the piece of glass and pulled along it.
The students notice that the vibrations of the tuning fork go "up and down" regularly. From this it can be concluded that tones are created when objects vibrate regularly.
Relevant for teaching:
Acoustic phenomena
Sound/acoustics: parameters
Vibrations and waves
Information and ideas:
To check that this assumption is correct, the following experiment can be carried out:
A piece of glass covered in soot is placed on an overhead projector. A tuning fork is struck and the point of one of the tines is put carefully on the piece of glass and pulled along it.
The students notice that the vibrations of the tuning fork go "up and down" regularly. From this it can be concluded that tones are created when objects vibrate regularly.
Relevant for teaching:
Acoustic phenomena
Sound/acoustics: parameters
Vibrations and waves
Tuning fork as “simple” sound (Video)
Example
Music; Personal, social and health education (PSHE); Physics
Grade 1 to 4; Grade 5 to 6; Grade 7 to 9; Grade 10 to 13
Elementary school; Middle/high school; Vocational training
Sound; Sound (basic phenomenon); Sound production; Type of sound
Siemens Stiftung Media Portal
MediaHouse GmbH
© Siemens Stiftung 2016
