Question

what sound wave we hear if tunning fork is vibrate

Answer 1

The primary way that tuning forks produce sound is by placing the stem of the vibrating tuning fork on a resonating chamber. The stem of the fork is also vibrating. This vibration is transmitted to the resonating chamber which then produces the sound.

A tuning fork serves as a useful illustration of how a vibrating object can produce sound. The fork consists of a handle and two tines. When the tuning fork is hit with a rubber hammer, the tines begin to vibrate. The back and forth vibration of the tines produce disturbances of surrounding air molecules.