How does a mechanical wave transfer energy?

Answer 1

A periodic wave is a periodic disturbance that moves through a medium. The medium itself goes nowhere. The individual atoms and molecules in the medium oscillate about their equilibrium position, but their average position does not change. As they interact with their neighbors, they transfer some of their energy to them. The neighboring atoms in turn transfer this energy to their neighbors down the line. In this way the energy is transported throughout the medium, without the transport of any matter.

The animation above portrays a medium as a series of particles connected by springs. As one individual particle is disturbed, it transmits the disturbance to the next interconnected particle. This disturbance continues to be passed on to the next particle. The result is that energy is transported from one end of the medium to the other end of the medium without the actual transport of matter. The individual atoms and molecules act like coupled harmonic oscillators.

Periodic waves are characterized by a frequency, a wavelength, and by their speed. The wave frequency f is the oscillation frequency of the individual atoms or molecules. The period T = 1/f is the time it takes any particular atom or molecule to go through one complete cycle of its motion. The wavelength is the distance along the direction of propagation between two atoms which oscillate in phase.