A plastic ruler is held firmly on a desk with $15\text{ cm}$ sticking out. When flicked, it hums. If the…

A plastic ruler is held firmly on a desk with $15\text{ cm}$ sticking out. When flicked, it hums. If the ruler is pulled back so that only $5\text{ cm}$ sticks out and flicked with the same force, what will change?
  1. It stops vibrating because it is too short
  2. It vibrates faster, producing a higher-pitched sound
  3. It vibrates slower, producing a lower-pitched sound
  4. It vibrates with greater amplitude, producing a louder sound

Solution

Shorter vibrating lengths oscillate at a higher frequency, which results in a higher pitch sound.

Asked in: Homi Bhabha Practice

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