Question

which characteristic of a vibrating body determines the (a) loudness (b) pitch of the sound produced by it?

Answer 1

-- The loudness of the vibration is determined by its amplitude.

-- The pitch of the vibration is determined by its frequency.

-- The amplitude and frequency of the vibration are determined by the material characteristics of the body that's vibrating, and by how much energy is used to start the vibrations.

Answer 2

The loudness depends on the amplitude of the vibration. It will be louder when the amplitude is high. Suppose when we pluck a string of the sitar it starts vibrating with low amplitude and if we apply more energy by plucking more strongly, the string will vibrate with the greater amplitude and produce a loud sound.

Hope this helps,

Davinia.