Question

Explain elastic wave in solid?

Answer 1

We'll now look at elastic waves in solids further. We will demonstrate that in an elastic medium, two types of waves can exist: longitudinal (compressional) and transverse (shear) waves, using the general equation of motion obtained in the previous chapter.

Complete answer:
As particles are displaced in a medium, they are acted upon by a force equivalent to the displacement to return them to their original position. The effect of a localised, sharply applied disturbance in a medium quickly spreads or transmits to other parts of the medium. This basic fact serves as the foundation for research into the fascinating topic of wave propagation.

The propagation of sound through the air, the spreading of ripples on a pond of water, the transmission of seismic tremors in the earth, and the transmission of radio waves are all examples of this phenomenon. The dissemination of disturbances in different media such as gas, liquid, and solid share several similar characteristics, so that anyone who is well-versed in one knows a lot about the others.

The interaction of the discrete atoms in the medium is the physical basis for the propagation of a disturbance. Except that such investigations are more tuned to physics than mechanics. The medium is considered continuous in solid as well as fluid mechanics, so properties like density and elastic constants are considered continuous functions describing averages of microscopic quantities.

Note: While solids can support transverse waves (also known as S-waves in seismology), longitudinal sound waves in solids have a velocity and wave impedance that are determined by the density and rigidity of the material, the latter of which is defined (as with sound in a gas) by the bulk modulus.