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Wave velocity - Wikipedia, the free encyclopedia Wave velocity is a general concept, of various kinds of wave velocities, for an electromagnetic wave's phase and speed concerning energy (and information) propagation. The relationship between group velocity and phase velocity is the dispersion relationship. The universal wave equation is v=fλ, where v is the speed the wave travels (in m/s), f is the frequency (in Hz, 1Hz=1/s), and λ is the wavelength (in m). en.wikipedia.org /wiki/Wave_velocity   (200 words)

News 3 All types of waves have some common features, such as the wave speed (how fast the wave moves), the amplitude of the wave, and the frequency or period of the wave. Note that for MOST waves, the speed of the wave is normally fairly constant and is independent of the wave frequency and amplitude. Deep water waves are waves that have a wavelength which is much smaller than the depth of the water. www.waveequation.com /wave_equation_data.html   (809 words)

#1 Site For Learning Science The wave propagates perpendicular to the motion of the particle. Thus a transverse wave is a wave in which the particles of the medium vibrate at right angles to the direction of propagation of the wave. Wave velocity is the velocity of the wave or it is the distance traveled by the wave in one second. home.att.net /~cat4a/wave-I.htm   (950 words)

Mathematica 5.0 Workbook Catalog The terminal velocity is found, and plots are made of the position and velocity of the projectile for various values of the drag force constant b. The parameters are ωh and ωv, the components of the angular velocity in the horizontal plane and in the vertical, and both are initially set to zero. The wave velocity is c, and the wavefronts have Gaussian shapes. www.fas.harvard.edu /~scidemos/Mathematica/Mathematica.html   (1566 words)

Wave Velocity Anisotropy, WVA The pressure dependent p-wave velocity anisotropy is used to separate crack caused anisotropy from anisotropy induced by texture. The strong increase of velocity in the region up to 100 MPa is caused by the closure of microcracks and pores. The next two diagrams show the anisotropy of p-wave velocity and the attenuation of the ultrasonic signals in a core sample in dependence on azimuth and confining pressure (1, 10, 40 and 175 MPa). www.kw-internet.de /wolter-dcm/wva.htm   (425 words)

wave terminology Often the material in a wave crest is referred to as a wave front. is proportional to the square of the wave amplitude. velocity of a mechanical wave is dependent on the elasticity and the inertia of the medium www.angelfire.com /sc/PhysicsPhascination/wavemot.html   (376 words)

Wave Space | StarLogo Models Library Online Observe how the propagation of average neighbors' height to the insulation patches tends to damp waves - reducing echo from and conduction through the insulation - by minimizing the sum of the differences in height between the insulation and its neighbors - and thus minimizing the change of velocity on the neighboring patches. Driver turtles already have a variable called "delay", which can be used to offset the wave produced by a driver; this can be used to compensate for the fact that a listener may hear the wave produced by one driver before that produced by another. In particular, the calculations by which the wave propagates through the membrane in this model are very similar to those used in the NetLogo model (although this model uses patches extensively, and the NetLogo model uses turtles for the membrane lattice). education.mit.edu /starlogo/models/library/WaveSpace   (2349 words)

Clinical Trial: Measurement of Pulse Wave Velocity in Spinal Cord Injury and Stroke Patients According to the theory of wave transmission, the speed of wave transmission is dependent on the nature of the transmission medium, which is the vessel wall for pulse wave transmission. The purpose of this project is to use the pulse wave velocity to measure the sympathetic activity of stroke and spinal cord patients. The present project plans to measure the pulse wave simultaneously at four limbs by pressure receptors, and use the electrocardiogram as the reference to synchronize the recorded pulse wave at different vessels, using the corrected data to calculate the pulse wave velocity. www.clinicaltrials.gov /ct/show/NCT00172289?order=16   (1197 words)

body The energy in a wave is one factor that helps determine the damage a tsunami causes. The velocity of the wave and its period. A wave velocity (meters/second) is calculated by multiplying the distance between two crests of the wave by frequency. library.thinkquest.org /C0110220/original/waves.html   (401 words)

Sound Waves In sound waves, p and ρ vary little from their steady values (by less than one part in a thousand), and v is much less than the phase velocity of sound. A plane wave propagating in a thermally stratified atmosphere can be represented by a ray normal to the wave front whose inclination to the horizontal changes so that the velocity with which the line of intersection of the wave front with a horizontal plane moves, called the trace velocity, is constant. Just as in the case of the refracted wave, the wavefront must also have a constant phase relation to the incident wave, and so its trace must be the same as the traces of the incident and refracted waves, and move with the same trace velocity. www.du.edu /~jcalvert/waves/soundwav.htm   (9029 words)

Eqk_Seismic waves Variations in seismic wave velocity are used to infer the properties of the earth’s interior. The amplitude of the recorded wave is proportional to the magnitude of shaking associated with the earthquake but shaking may vary with the character of the material underlying the seismograph station. The difference in arrival time between P and S waves on a seismogram can be used to determine the distance of the station from the earthquake source and the amplitude (height) of the S wave recorded at the station can be used to determine earthquake magnitude (see Earthquake measurement). www.mhhe.com /earthsci/geology/mcconnell/earthquakes/swaves.htm   (917 words)

Phase, Group, and Signal Velocity The velocity of a wave can be defined in many different ways, partly because there many different kinds of waves, and partly because we can focus on different aspects or components of any given wave. It's entirely possible for a wave to "precess" through a sequence of material entities, none of which is moving in the direction of the wave. Since a general wave (or wavelike phenomenon) need not embody the causal flow of any physical effects, there is obviously there is no upper limit on the possible phase velocity of a wave. www.mathpages.com /home/kmath210/kmath210.htm   (1990 words)

Higher-Order Wave Equations and Matter Waves   (Site not responding. Last check: 2007-10-10) This suggests that we might regard a particle of mass m and velocity V as a "matter wave" with the frequency w and wave number k proportional to the energy and momentum respectively, in accord with the above equations for E and p. In other words, we must decide if we are interested in the wave that corresponds to the total energy of the particle, or in the wave that corresponds to just the kinetic energy associated with the motion of the particle. The complex-valued wave function (3) is a solution of every one of these equations, but the equations are nevertheless distinct, as illustrated by the fact that although every solution with s = 1 is also a solution with s = 0, the converse is not true. www.mathpages.com /home/kmath415/kmath415.htm   (1570 words)

AtCor Medical - Pulse Wave Velocity Pulse wave velocity is a well-established technique for obtaining a measure of arterial stiffness between two locations in the arterial tree. The velocity of the pulse wave along an artery is dependent on the stiffness of that artery. This aortic pulse wave velocity increases rapidly with age, typically doubling between the ages of 30 and 60. www.atcormedical.com /sphygmocor_vx.html   (314 words)

gls214_waves Ocean waves with the longest periods are tidal wave produced by the gravitational forces exerted on the Earth by the Moon and Sun. Swell waves are uniform in length and period and have a narrow spectrum. crest exceeds the wave celerity, or velocity at the trough. w3.salemstate.edu /~lhanson/gls214/gls214_waves.html   (2046 words)

Group velocity - Wikipedia, the free encyclopedia For example, it is possible to design experiments where the group velocity of laser light pulses sent through specially prepared materials significantly exceeds the speed of light in vacuum. This "group velocity dispersion" is an important effect in the propagation of signals through optical fibers and in the design of short pulse lasers. The velocity of a particle, he concluded, should always equal the group velocity of the corresponding wave. en.wikipedia.org /wiki/Group_velocity   (472 words)

IngentaConnect Teleseismic surface wave study for S-wave velocity structure unde...   (Site not responding. Last check: 2007-10-10) Surface wave phase velocity measurements are achieved by way of a waveform-matching spectral-domain technique that was developed for use within the CISN array. A two-station phase velocity measurement technique was developed, which takes advantage of the fact that, for surface wave arrivals from any azimuth, there are multiple pairs of CISN stations, which are almost exactly on the same great-circle paths. A slow velocity anomaly is evident under the Southern Sierras and the Salton Sea, the latter region indicating the northward extension of tectonic activity in the Gulf of California. www.ingentaconnect.com /content/bsc/gji/2006/00000166/00000002/art00010   (479 words)

Wave Equation, Wave Packet Solution A traveling wave solution to the wave equation may be written in several different ways with different choices of related parameters. The wave velocity is determined by the properties of the medium and is independent of the other parameters, but it can be determined from measurements of the frequency and wavelength. In the case of classical waves, either the real or the imaginary part is chosen since the wave must be real, but for application to quantum mechanical wavefunctions such as that for a free particle, the complex form may be retained. hyperphysics.phy-astr.gsu.edu /hbase/waves/wavsol.html   (390 words)

CUB model main page CUB shear velocity model is created from a large data set of the surface wave fundamental model phase and group velocity measurements. The group velocity measurements at periods between 16 and 200s are performed at the Center for Imaging the Earth's Interior in the University of Colorado at Boulder. The group velocities are measured with the frequency-time analysis (Levshin et al., 1989) in which for every waveform a human analyst defines the frequency range of measurements and separate the signal form a variety of noise sources (e.g., overtones, fundamental modes of different types, other earthquakes, multipaths, scattered arrivals). ciei.colorado.edu /~nshapiro/MODEL/index.html   (1362 words)

Standing Waves on a String The fundamental vibrational mode of a stretched string is such that the wavelength is twice the length of the string. The velocity of a traveling wave in a stretched string is determined by the tension and the mass per unit length of the string. When the wave relationship is applied to a stretched string, it is seen that resonant standing wave modes are produced. hyperphysics.phy-astr.gsu.edu /hbase/waves/string.html   (358 words)

Global models of Surface Wave Group Velocity   (Site not responding. Last check: 2007-10-10) Measurements of group velocity are derived from phase velocity dispersion curves and are modeled with global laterally-varying isotropic structure. The group velocity maps from this study are compared for the area of Eurasia with the maps of Ritzwoller and Levshin [1998]. The coefficients of the group velocity models and images of the models are also available. www.seismology.harvard.edu /projects/surfwave/LE00-Pageoph/summary.html   (299 words)

Catching Waves to Spot Cardiovascular Risk - CME Teaching Brief® - MedPage Today ROCHESTER, Minn., Feb. 21-- Aortic pulse wave velocity, an experimental non-invasive method for testing the health of coronary arteries, appears to be a good predictor for the presence of atherosclerosis and cardiovascular risk. Inform interested patients that aortic pulse wave velocity, a quick, painless, and non-invasive method for measuring arterial stiffness, appears to be a good predictor of cardiovascular risk, but needs to be validated in further testing with larger populations. Aortic Pulse Wave Velocity Is Associated With the Presence and Quantity of Coronary Artery Calcium: A Community-Based Study. www.medpagetoday.com /Cardiology/AcuteCoronarySyndrome/dh/2722   (832 words)

Surface Waves Then, the time derivative of the velocity potential is equal to the potential of the external forces, here gravitation, when evaluated at the free surface, where the pressure is constant regardless of displacement, and may be taken as zero. This wave is indeed sinusoidal in a sense (φ varies sinusoidally with x and t), but the wave shape is not sinusoidal. The energy in the wave is moving at the speed of the group, not at the phase velocity of the waves. www.du.edu /~jcalvert/waves/surfwave.htm   (1857 words)

Wave Mechanics; Animated de Broglie phase wave   (Site not responding. Last check: 2007-10-10) Note that the speed of the phase wave (phase velocity) exceeds that of the particle (group velocity). Note that, in accordance with the de Broglie theory, the phase of the phase wave at the position of the particle always exactly matches the instantaneous phase of the internal periodic phenomenon associated with the particle, though (except for massless particles) the particle and the phase wave move, or propagate, with different velocities. The constant match between the phase of the phase wave and the phase of the internal periodic phenomenon at the position of the particle is illustrated above by the invariable coincidence of the www.davis-inc.com /physics/wavegrph.html   (398 words)

Earthquakes: Seismic Waves P waves travel at speeds of 4 to 6 km per second (2.5-4 miles per second) in the uppermost part of the crust. S wave velocity is 3 to 4 km per second (2-2.5 miles per second) in the shallow crust. P waves are similar to the passage of a vibration through a slinky. www.mhhe.com /earthsci/geology/mcconnell/eqk/swaves.htm   (959 words)

Doppler Distortion: Piston Vibrating in a Tube Including the Effect of Excursion Thus the piston velocity of equation (2) does not match the sound wave velocity of equation (3) at the interface of the piston and the air. The necessary and sufficient conditions for an exact solution for the sound wave are: (1) the solution satisfies the wave equation, and (2) the wave velocity equals the piston velocity at the piston face. At the wave peaks, the molecules, on average, are moving forward. www.silcom.com /~aludwig/Physics/Exact_piston/dopdist.htm   (2630 words)

Reference Shear Wave Velocity Profiles Regional and local reference profiles were developed for the Upper Mississippi Embayment based on measured shear wave velocity profiles that were compiled for the Central United States.   The compiled shear wave velocity profiles were grouped based on the age of near-surface geologic deposits and geographic location.   The shear wave velocity of the Paleozoic basement that underlies the embayment was based on Catchings (1999) and given as 2040 m/s. www.ce.gatech.edu /~sromero/maecenter/profiles1.html   (675 words)

Wagner Research Laboratory   (Site not responding. Last check: 2007-10-10) This velocity is close to the velocity that I observed for W-waves traveling through salt solution filled wood samples as well as to the velocity of W-waves in live plants. This looks like the work of a wave phenomenon where the wave velocity increases exponentially as it travels away from the sun or planets due to a decreasing density of the wave medium. The velocity of W-waves in ordinary matter (with dark matter present) seems to be inversely proportional to the square root of the density of the medium if one leaves out velocity switching discussed earlier. www.chatlink.com /~oedphd/cosmology/article.html   (3635 words)

P- and S-Wave Velocity Results Seattle area average S-wave velocities to 30-m depth projected onto the surficial geologic map of Seattle shown in Figure 1. The lowest S-wave velocities were found in the Duwamish industrial area, which is located on mostly artificial fill at the surface. Because the S-wave refraction phases were poorly developed or nonexistent in the upper 20 m at KD1 and KD2, velocities were determined primarily from the reflection data. earthquake.usgs.gov /regional/pacnw/siteresp/svel/1997/results.html   (331 words)

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