Which statement explains why sound waves cannot be polarised?
Answer and explanation
Correct answer: D. Sound waves are longitudinal
- Step 1: Polarisation restricts oscillations to one plane perpendicular to the direction of travel.
- Step 2: A longitudinal wave oscillates along its direction of travel, so there is no transverse plane to select.
Answer
Sound waves are longitudinal.
Why not the others: Sound waves are too low in frequency to be affected by a polarising filter: frequency is irrelevant; the issue is the direction of oscillation. Sound waves carry no energy in the direction of travel: they do carry energy along their direction of travel. Sound waves are electromagnetic waves with a very long wavelength: sound is a mechanical wave, not electromagnetic.
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