A mechanical or material wave is a wave that needs a medium to travel. The oscillating material does not move far from its initial equilibrium position, as only the energy is transferred by connected particles. Ocean waves and sound are examples of this phenomenon.
A mechanical wave requires an initial energy input. Once this initial energy is added, the wave travels through the medium until all its energy is transferred. Electromagnetic waves require no medium, but can still travel through one.
There are three types of mechanical waves: Transverse waves, longitudinal waves, and surface waves. Transverse waves cause the medium to vibrate at a 90-degree angle to the direction of the wave. Transverse waves have two parts—the crest and the trough. The crest is the highest point of the wave and the trough is the lowest. The wavelength is the distance from crest to crest or from trough to trough.
A torsional wave is a two-dimensional transverse wave. This type of wave twists along a given medium. For example: if you twist a coil on one end and release it, the "twist" travels in a wave to the other end of the coil.
Pressure waves travel faster through solids and liquids than through gases such as air.
The final type of wave is a surface wave. This type of wave travels along a surface that is 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.
One important property of mechanical waves is that their amplitudes possess an unusual form, displacement divided by reduced wavelength. When this gets comparable to unity, significant nonlinear effects such as harmonic generation may occur, and, if large enough, may result in chaotic effects. For example, waves on the surface of a body of water break when this dimensionless amplitude exceeds 1, resulting in a foam on the surface and turbulent mixing.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Wave–particle duality — Quantum mechanics Uncertainty principle … Wikipedia
Wave — A wave is a disturbance that propagates through space and time, usually with transference of energy. While a mechanical wave exists in a medium (which on deformation is capable of producing elastic restoring forces), waves of electromagnetic… … Wikipedia
wave — Synonyms and related words: Afro, accost, address, advertise, affect, air, ambages, amplitude, anfractuosity, antinode, barber, be poised, beat, beat the drum, betoken, bicker, billow, blazon forth, bob, bobble, bore, bow, brandish, brandishing,… … Moby Thesaurus
wave function — Physics. 1. a solution of a wave equation. 2. (in quantum mechanics) a mathematical function, found by solving a quantum mechanical wave equation, that is used to predict the outcome of measurements on physical systems. * * * Variable quantity… … Universalium
Mechanical Man EP — EP by Devo Released 1978 Recorded April 1974 July 1976 Genre New Wave, Post punk … Wikipedia
Mechanical index — (MI) is an ultrasound metric. It is defined as  where: PNP is the peak negative pressure of the ultrasound wave (MPa) Fc is the center frequency of the ultrasound wave (MHz) Mechanical index can be used as an estimate for the degree of bio… … Wikipedia
Wave power — refers to the energy of ocean surface waves and the capture of that energy to do useful work including electricity generation, desalination, and the pumping of water (into reservoirs). Wave power is a form of renewable energy. Though often co… … Wikipedia
Wave Dragon — is a floating slack moored energy converter of the overtopping type, located in the northern Denmark. It was the world s first offshore wave energy converter. Wave Dragon is a joint EU research project, including partners from Austria, Denmark,… … Wikipedia
Wave soldering — is a large scale soldering process by which electronic components are soldered to a printed circuit board (PCB) to form an electronic assembly. The name is derived from the use of waves of molten solder to attach metal components to the PCB. The… … Wikipedia
Mechanical Galleon — Material Gilt brass, steel and other materials Size 78.5cm long and 104 cm high Created c. 1585. in Augsburg … Wikipedia