Question

'Sound waves need a medium for propagation'. Explain with the help of a demonstration.​

Answer 1

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. Sound cannot progress through the vacuum because the vacuum has no molecules which can vibrate and carry the sound waves.

Answer 2

Bell jar experiment is used to demonstrate that sound needs a medium to travel . Place an electrical bell in the bell jar and pump out the air of the sealed bell jar. Turn on the electric bell. This demonstrates that the sound waves cannot travel through vacuum and it needs a material medium for its propagation.