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.

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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)

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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

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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

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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.

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