PRODUCTION OF SOUND WAVES

In day to day life we understand the meaning of sound .But in laboratory if we have to produce sound in restricted condition then it is produced by a tuning fork. when we  strikes tuning fork itproduce different sounds. But in day to day life sound can also be produced by plucking a stretched string (violin), by blowing flute, by striking tabla and many other ways. let us perform the following two simple experiments to understand sound vibration.

FIRST EXPERIMENT :

On striking a school bell B (shown in the figure )with a hammer, it produces sound. On touching the bell B with finger, we feel that the bell is in a state of vibration. If a pith-ball P is suspended near the bell B then the pith-ball, P, suspended near the bell moves from its equilibrium position P to P′ as shown in figure.

In the above experiment we have produced sound by plucking and striking. We can also produce sound by different source and  scratching, rubbing, blowing, shaking, etc.

Thus, we conclude that sound is produced by setting the objects in vibration. Vibration means a kind of rapid to and fro motion of an object.

SECOND EXPERIMENT :

Like a guitar if we Strike a metallic wire AB between two nails fixed on a table. When we pluck the wire anywhere between AB a sound is heard. If a V-shaped small paper rider (R) is placed near the centre of the wire, it starts vibrating. If the rider is placed at the centre of the wire, it suddenly flies off. This experiment also shows the vibration on wire.