Wave motion can be classified base on Mode of Propagation The class of waves

Wave motion can be classified base on mode of

This preview shows page 77 - 82 out of 260 pages.

particle of the medium travelling between the two points. Wave motion can be classified base on: Mode of Propagation The class of waves under this is Mechanical wave: this requires a material medium for propagation Electromagnetic wave: This travels in a vacuum Mode of vibration The class of waves under this is: Longitudinal waves Transverse waves Diagrammatic representation of waves Definition of terms Period (T): it is the time taken for a particle to undergo one complete cycle of oscillation. Frequency (f): it is the number of oscillations performed by a particle per unit time. Wavelength (λ): it is the distance between any two successive particles that are in phase, e.g. it is the distance between 2 consecutive crests or 2 troughs. Wave speed (v): The speed at which the waveform travels in the direction of the propagation of the wave.
Image of page 77
Servantboy.com 78 Wave front: A line or surface joining points which are at the same state of oscillation, i.e. in phase, e.g. a line joining crest to crest in a wave. Displacement: it is the Position of an oscillating particle from its equilibrium position. Amplitude: it is the maximum magnitude of the displacement of an oscillating particle from its equilibrium position. To deduce V = fλ no of cycle = n time = Tn distance = λ n substitute all into the velocity = distance/time Note F is the frequency and the S.I base unit is Hertz (Hz)
Image of page 78
Servantboy.com 79 T is the period and the S.I base unit is second(s) λ is the wavelength and the S.I base unit is meter(m) Therefore, V = fλ Displacement-distance graph and Displacement-time graph The first graph is a displacement-distance graph. On this graph you can find wavelength and amplitude The second graph is a displacement-time graph. On this graph you can find period, frequency and amplitude The only difference between the two graphs is what you can calculate from it. Phase difference: this is an amount by which one oscillation leads or lags behind another. it measures in degree or radian. Phase difference between waves that are exactly out of phase is π radians or 180 degrees
Image of page 79
Servantboy.com 80 Progressive wave: it is a propagation of energy as a result of vibrations of waves which move energy from one place to another. Intensity: it is defined as power incident per unit area. The intensity of wave generally decreases as it travels along. The two reasons for this are: The wave may spread out The wave may be absorbed or scattered As wave spread out, its amplitude decreases The unit of intensity is I is the intensity A is amplitude f is frequency r is the distance from the source Difference between Longitudinal waves and Transverse waves Transverse waves: A wave in which the oscillations of the wave particles are perpendicular to the direction of the propagation of the wave. Light wave is an example of transverse waves
Image of page 80
Servantboy.com 81 Longitudinal waves: A wave in which the oscillations of the wave particles are parallel to the direction of the propagation of the wave. Sound wave is an example of longitudinal wave Transverse waves can be plane polarized while longitudinal waves cannot be plane polarized.
Image of page 81
Image of page 82

You've reached the end of your free preview.

Want to read all 260 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture