1. Nature of Sound Waves

Sound is one kind of longitudinal wave, in which the particles oscillate to and fro in the same direction of wave propagation. Sound waves cannot be transmitted through vacuum. The transmission of sound requires at least a medium, which can be solid, liquid, or gas.

 

condensation

rarefaction

 

The wavelength, l is the distance between two successive rarefactions or condensations.

 

Figure 1 Propagation of Sound Wave

 

The displacement of any point on the wave, y, along the direction of propagation is related to time by the following formula:

(1)

(2)

(3)

(4)

Table 1 shows the velocities of sound in same common media.