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Propagation of sound through a medium:
  • From the point of production to the receiver end, sound requires a medium to travel.
  • The different mediums of propagation of sound are air, liquid and solid.
  • Because there is no medium of transmission, sound cannot travel through vacuum.
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Travel of sound through air medium
 
 
Important!
Medium: A substance through which energy of some kind can travel.
Example:
Solid, Liquid, Gas.
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Variation of molecules in different medium  
  
Sound cannot travel in a vacuum:
  • Sound cannot travel in a vacuum because sound waves always need molecules of some kind to travel in a given space.
  • Sound produced by a source travels from one point to another by transmitting the energy through the molecules of the medium around it. This is why sound does not travel through a vacuum, where there are no molecules in it.
Travel of sound in liquid:
  • The sound waves move through solid, liquid and gas by vibrating the molecules in the matter.
  • In water, sound travels four times faster than it does in the air. Sound moves faster in water than air because water particles are packed very tightly compared to air.
  • Thus, the energy the sound waves carry is transported faster.
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Sound wave in liquids
Travel of sound in liquids:
  • The sound waves move through different mediums by vibrating the molecules in it.
  • The molecules in the solids are packed very tightly when compared to liquid as well as gas.Thus it enables sound to travel much faster through a solid than gas and liquid.
  • Sound travels \(13\) times faster in solid than through the air.
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Sound wave in solids
Reference:
https://www.scientificamerican.com/arabic/articles/bring-science-home/what-do-you-hear-underwater/
https://rajasthanboardd.blogspot.com/2019/05/cbse-class-8-why-do-we-need-parliament.html
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