Prove that the sound is produced from a vibrating source.

Explanation

1) Attach a small piece of steel wire to one of the prongs of a tuning fork as shown in the figure.
2) Strike the tuning fork with a rubber hammer.
3) While it is vibrating, try to draw a straight line on a piece of smoked glass as quick as posiible with it.
4) Keep the end of the wire in such a way just it touches the glass.
5) A line is formed in the form of a wave.
6) Repeat the experiment when the tuning fork is not vibrating and observe the difference in the line.
Observations :
1) We have produced vibrations in the tuning fork by striking it with a hammer.
2) Thus the vibrating tuning fork produces sound.
3) Thus the sound is produced by vibrating bodies.