Back again to the waves on a string, where you can see, that wave runs right, and each point of the cord moves up or down around the equilibrium position. Wave, where variations occur Wednesday particles perpendicular to the direction of wave propagation, called transverse. They consist of a series of alternating bulges and depressions.

As said above, that cord, When it runs the wave, shear strain occurs, the consequence of which is the change in body shape. Transverse waves are possible only in the case, When changing forms accompanied by the advent of elastic return force. Since this property only the solids and the liquid surface, transverse waves can occur only on the surfaces of solids and liquids (rice. 24.17).

In nature there are waves and other type. If you take a long spring and push it along the axis, as shown in figure. 24.18, then on it will run as a wave moving condensations and vacuum it turns. In this example, the wave runs right, and each revolution Springs varies along its axis. Wave, in which the particle fluctuations occur in a straight line, along which the wave spreads, referred to as the uprights. Shift of particles in this wave occurs on line, connecting their centres, t. e. causes a change in the volume of. Since the return of force when you change the volume not only occur in solids and liquids, but in gases, longitudinal waves are possible in solids, liquids and gases.