Q1
What type of wave is sound?
ALongitudinal
BTransverse
CNeither type
DBoth types equally
ICSEClass 9 (ICSE)PhysicsCh 8 · Topic 1
Propagation of Sound Waves
Sound waves propagate through a medium as longitudinal waves, requiring compressions and rarefactions to travel from source to receiver.
Core concept
Sound waves are longitudinal, meaning particles vibrate parallel to the direction the wave travels, creating compressions (dense regions) and rarefactions (sparse regions).
How it works
Sound cannot travel through a vacuum since it requires a medium (solid, liquid, or gas) with particles to transmit vibrations.
Why it matters
The speed of sound varies by medium and temperature, travelling faster in solids than liquids, and faster in liquids than gases.
Key detail
Understanding sound wave propagation explains phenomena like echoes, the Doppler effect, and how we hear sounds from different sources.
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• Sound waves are longitudinal.
• Particles vibrate parallel to wave direction.
• This creates compressions and rarefactions.
• Sound needs a medium to travel.
• It cannot travel through a vacuum.
• Speed varies: fastest in solids, slowest in gases.
• This explains echoes and the Doppler effect.
• It also explains how we hear different sounds.