Practice question · True or false
Sound waves in air are transverse waves: air molecules oscillate perpendicular to the direction of travel.
Hints
- Can air support a shear stress?
- Compressions and rarefactions.
Show the answer
False
Why
False. Sound in air is longitudinal: molecules oscillate parallel to the travel direction, producing compressions and rarefactions. Fluids cannot sustain shear, so they carry no transverse waves at all; that is why seismic S-waves stop at the Earth's liquid outer core, which is how we know it is liquid.
Practise Sound Waves and the Doppler Effect
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