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Wednesday, April 21, 2010 12:01 PM

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Characteristics of Waves:

Wave speed (v) is the velocity of the wave as it moves through a medium. Wave speed is also known as the propagation speed of the wave. The speed of a wave is expressed in m/s.

Speed on a string (transverse): where F is the tension (N), m/L is the mass per unit length (Kg/m)

Speed through a metal rod (longitudinal): where Y is young’s modulus (N/m2) and ρ is the density (usually in units of Kg/m3).

Speed through a gas or liquid: Where β is the bulk modulus and ρ is the density.

Wavelength (λ) is the distance between corresponding points on adjacent wave pulses. The wavelength of a wave is expressed in linear units, usually meters.

Frequency (ƒ) is the number of complete waves, which pass through a point in space per unit time. The frequency of waves is measured in Hertz (Hz). An older but more descriptive unit is cycles per second (cps).

The period (T) of a wave is the time required for a complete wave to pass through a point in space. The period is the inverse of the frequency ( T = 1 / ƒ ). The period of a wave is measured in seconds.

Amplitude (a) is the maximum displacement experienced by a particle as the result of a wave. The amplitude is a measure of the energy carried by a wave. The units for amplitude are specialized for the type of wave. The amplitude of waves at the beach can be measured in meters. The amplitude of sound waves is measured in a unit of pressure such as Pascals. Amplitude is independent of the other wave characteristics.

The wave equation ( v = ƒ x λ ) expresses the relationship between wave speed (v), frequency ( ƒ ), and wavelength (λ). The wave equation shows that frequency and wavelength are inversely proportional. The wave equation is useful in many different applications and may be utilized in the analysis of matter waves as well as electromagnetic waves. http://web.me.com/dtrapp/ePhysics.f/WDwaves.html shahirah