Mechanical waves are disturbances that move through a medium, such as sound in air or seismic waves in rock. There are three types: transverse, longitudinal, and boundary. Waves have characteristics of frequency, period, wavelength, and amplitude. Transverse waves move up-and-down or side-to-side, longitudinal waves move through the expansion and compression of particles, and boundary waves resonate between two dissimilar mediums.
A mechanical wave is a disturbance that pulses through some form of medium – a solid, liquid or gas – carrying the original energy from one place to another. There are three types of mechanical waves: transverse, longitudinal and boundary. Simple examples of waves and the means by which they move are sound in air, seismic waves in rock, and the vibrations of a guitar string.
An example of mechanical waves are ripples in a pond that move outward from where a stone is dropped. The wave moves through the medium even though the atoms and molecules of the medium itself generally return to their original positions after they are squeezed together, stretched or rotated by the wave passing through them. The mechanical wave can move in straight-line motion, rotational motion, or a combination of the two.
Waves possess the characteristics of frequency, period, wavelength, and amplitude. The distance between one wave pulse and the next is its wavelength, and the time between pulses is the period. For shear waves, the amplitude is the distance the wave displaces the medium. The number of waves that pass through the medium over time is the frequency of the wave. The higher the frequency of a mechanical wave, the more energy it transmits.
Transverse waves transmit their energy in an up-and-down or side-to-side fashion, forcing the medium to take the shape of a crest and trough, as in a sine wave. A good example of this type of wave is a seismic S-wave in which the earth’s crust moves up and down, or side to side, perpendicular to the direction of the wave’s propagation. The mechanical wave pattern of a transverse wave is given by the wave equation, an energy equation, the solution of which is a sine wave possessing the above characteristics of frequency, period, wavelength and breadth.
Longitudinal waves are density waves that move through the expansion and compression of particles in the medium. An expansion and a compression are a wavelength. Good examples of these waves are sound waves in the air and seismic P-waves in the ground. The higher the density of the material, the faster the waves move through it.
Boundary waves are mechanical waves that resonate between two dissimilar mediums. The air pockets and bound strings in musical instruments, the vibration of a tuning fork and the corona shape of a water droplet are good examples of mechanical boundary waves. The resonant sound of the tuning fork is limited by the shape and size of its contour and the elasticity of the material that composes it.
Protect your devices with Threat Protection by NordVPN
