Question

Why we can not hear the sound of pendulum?

Answer 1

we can not hear the sound of pendulum because the frequency of vibrations produced by a pendulum does not fall under human ear's audible range as our audible range starts from 20Hz to 20000Hz
 

Answer 2

Pendulum does produce a sound but humans can't hear the sound.

This is because hearing range of human is 20 Hz - 20,000 Hz.We won't be able to hear sounds of frequency less than or greater than that.

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