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Sound — Science STD 9 — Question

Gujarat BoardEnglish MediumSTD 9ScienceSound2 Marks
Question
What are infrasonic waves? Name two animals which produce infrasonic waves.
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Answer

Infrasonic waves: Infrasonic waves include sounds of frequencies below 20Hz. These sounds are produced by objects vibrating very slowly.
Whales and elephants can produce these sounds.

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