Question

Describe a simple experiment to show that sound cannot propagate through vacuum

Answer 1

The Bell-Jar Experiment
Objective :
To show sound can't propagate through vacuum
Apparatus Required :
1) A glass jar
2) Electronic Bell
3) Vacuum pump
4) Switch (electric connection)
Procedure :
1) An electric bell is taken inside an airtight glass jar.
2) It is suspended inside the jar.
3) The jar is connected to a vacuum pump.
4) The switch is on and air is started to be pumped out.
Observations :
1) At first we can hear the sound of bell clearly.
2) As soon as air is pumped out, the sound of bell starts to become feeble
3) After the air is completely vacated out, no sound is heard.
Conclusion :
This means as a vacuum is created in the jar, no sound is heard. This means sound always requires a material medium to travel.