Cite an experiment to show that sound needs a material medium for its propagation.

To do:

To cite an experiment to show that sound needs a material medium for its propagation.

Objects required:

An air-tight jar, a ringing bell, and a vacuum pump.

Experiment:

Let us do an experiment in two actions to show that sound needs a material medium for its propagation:

Action 1:

Let us place a bell in an airtight jar and ring the bell.

Observation:

On ringing the bell, the sound is heard clearly. Hearing this sound proves that sound can travel in the air as the air is present in the jar.

Action 2:

Let us place a bell in an air-tight jar that is connected to a vacuum pump. Let us ring the bell.

Observation:

We do not hear any sound. On observation, it is found that sound is not bearable even after ringing the bell placed in an air-tight jar that is connected to a vacuum pump. It means that sound cannot travel in a vacuum.

Conclusion: 

Based on the above two experiments we can conclude that sound needs a material medium for its propagation.