Question

Why is sound not a transverse wave?

Answer 1

Hint: In order to answer the above question we need to know what are transverse waves and the properties of such a group of waves. Further we also need to know what are the characteristics of sound waves that are used to classify waves into various groups of waves. Hence having the above information will enable us to know why sound waves are not classified as transverse waves.

Complete step-by-step solution:
To begin with let us first see how various types of waves are usually classified.
Depending on the relationship between the direction of oscillation of the individual particles and the direction of wave propagation, the waves are classified into two categories : transverse waves and longitudinal waves.
Transverse waves are the waves in which the individual particles of the medium oscillate perpendicular to the direction of wave propagation. Whereas the longitudinal waves are the waves in which the particles of the medium oscillate along the direction of wave propagation.
Sound wave is a mechanical wave. It propagates in air in producing alternate regions of compression and rarefaction. The particles of the medium in a region of compression have higher density as compared to the region of rarefaction. From this we can conclude that the particles of the medium oscillate back and forth in the direction of propagation moving from regions of higher to lower density.
Hence from the above information we can conclude that sound waves are longitudinal waves. Therefore we cannot categorize a sound wave as a transverse wave.

Note:Mechanical waves are the type of waves which require a medium for their propagation. Another example of longitudinal waves is compression moving on a slinky. We can make a horizontal longitudinal wave by pushing and pulling the slinky.