ABSTRACT
The energy introduced by the disturbance travels as kinetic energy of the particle motion and potential energy of particle displacement in the wave motion. As a wave propagates through an infinite medium, it tends to spread out and this introduces
1 INTRODUCTION
Physically, waves are a travelling disturbance and represent the transfer of energy from one point to another in a given medium. Thus, for a wave to exist, there must be an initial disturbance of the medium, that is, some forces must act to disturb the medium from its equilibrium position and thereby introduce new energy into the medium. The action of the forces causes the nearby portions of the medium to oscillate about their rest position, much as a spring mass system. The oscillatory disturbance is transmitted from one particle to an adjacent particle, then to the next and so on, causing a wave motion to propagate through the medium. There is no bulk movement or transport of mat-
a geometrical effect on the energy concentration of the wave. Thus in a perfectly elastic medium of infinite extent; a point source in such a medium would induce spherical waves. The area of these wave fronts increases as r2 (where r is the distance from the source), so the energy flow per unit area decreases as 1/r2.
