Editing Mechanical wave

{{short description|Wave which is an oscillation of matter}}
{{More citations needed|date=April 2013}}
[[File:Espejo (3207185886).jpg|thumb|right|250px|Ripple in water is a surface wave.]]

In [[physics]], a '''mechanical wave''' is a [[wave]] that is an oscillation of [[matter]], and therefore transfers energy through a [[transmission medium|material medium]].<ref>Giancoli, D. C. (2009) Physics for scientists & engineers with modern physics (4th ed.). Upper Saddle River, N.J.: Pearson Prentice Hall.</ref> 
(Vacuum is, from classical perspective, a non-material medium, where [[electromagnetic radiation|electromagnetic waves]] propagate.) 

While waves can move over long distances, the movement of the medium of transmission—the material—is limited. Therefore, the oscillating material does not move far from its initial equilibrium position. Mechanical waves can be produced only in media which possess [[Elasticity (physics)|elasticity]] and [[inertia]]. There are three types of mechanical waves: [[transverse wave]]s, [[longitudinal wave]]s, and [[surface wave]]s. Some of the most common examples of mechanical waves are water waves, sound waves, and [[seismic waves]].

Like all waves, mechanical waves transport [[energy]]. This energy [[Wave propagation|propagates]] in the same direction as the wave. A wave requires an initial energy input; once this initial energy is added, the wave travels through the medium until all its energy is transferred. In contrast, [[electromagnetic radiation|electromagnetic waves]] require no medium, but can still travel through one.

==Transverse wave==
{{Main|Transverse wave}}
A transverse wave is the form of a wave in which particles of medium vibrate about their mean position perpendicular to the direction of the motion of the wave.

==Longitudinal wave==
{{Main|Longitudinal wave}}
Longitudinal waves cause the medium to vibrate parallel to the direction of the wave. It consists of multiple compressions and rarefactions. The rarefaction is the farthest distance apart in the longitudinal wave and the compression is the closest distance together. The speed of the longitudinal wave is increased in higher index of refraction, due to the closer proximity of the atoms in the medium that is being compressed. [[Sound]] is an example of a longitudinal wave.

==Surface waves==
{{Main|Surface wave}}
This type of wave travels along the surface or [[interface (matter)|interface]] between two media. An example of a surface wave would be waves in a pool, or in an ocean, lake, or any other type of water body. There are two types of surface waves, namely [[Rayleigh wave]]s and [[Love wave]]s.

Rayleigh waves, also known as ''ground roll'', are waves that travel as ripples with motion similar to those of waves on the surface of water. Such waves are much slower than [[body wave (seismology)|body wave]]s, at roughly 90% of the velocity of {{clarify span|text=bulk waves|explain=What are "bulk waves"?|date=October 2018}} for a typical homogeneous elastic medium. Rayleigh waves have energy losses only in two dimensions and are hence more destructive in [[earthquake]]s than conventional bulk waves, such as [[P-wave]]s and [[S-wave]]s, which lose energy in all three directions.

A Love wave is a surface wave having horizontal waves that are shear or transverse to the direction of propagation. They usually travel slightly faster than Rayleigh waves, at about 90% of the body wave velocity, and have the largest amplitude.

==Examples==
*[[Seismic wave]]s
*[[Sound]] waves
*[[Wind wave]]s on seas and lakes
*[[Vibration]]

==See also==
*[[Acoustics]]
*[[Ultrasound]]
*[[Underwater acoustics]]

==References==
{{Reflist}}

{{Authority control}}

[[Category:Waves]]
[[Category:Mechanics]]