When we start filling an empty bucket with water, the pitch of sound produced goes on changing. Why?

Assertion : When we start filling an empty bucket with water, the pitch of sound produced goes on decreasing. Reason : The frequency of man voice is usually higher than of woman.

A person deep inside water cannot hear sound produced in air. Why?

When do we say that a bucket is bigger than a cup?

When do we say that a bucket is bigger than a cup?

Assertion (A) : The pitch of the sound produced by the vibrating string can be changed. Reason (R) : The pitch of the sound can be changed by changing the length, tension and thickness of the vibrating string.

Cracker on ignition produces sound. Why?