sound waves need a medium for propagation explain with the help of a demonstration

Dear student

Sound waves can not travel in vacuum as there is no medium and sound needs a material medium for their propagation like solid, liquid or gas to travel because the molecules of solid, liquid and gases carry sound waves from one point to another.

It's simple activity which would explain that sound waves require medium for propagation

  1. Take a bell jar. Bell jar is a laboratory equipment used for creating a vacuum. Its shape is similar to that of a bell.
  2. Place an electric bell in the bell jar.
  3. Start pumping out the air of the sealed bell jar. As we start pumping out the air, the sound of an electric bell coming out of bell jar starts fading.
  4. As soon as the vacuum is achieved in the bell jar, no more sound will be audible from the bell jar. However, in the bell jar, hammer continues to hit the gong.

It is clear from above activity that sound is produced but we are not able to hear as sound waves require medium for propagation but there is no vacuum inside jar. Hence we are not able to hear sound

So its proved from above demonstration that sound waves require medium for propagation

With Regards

  • -1
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