Oscillation (cycle) Fig 10.6: Terms used to describe periodic travelling waves
All the features of longitudinal waves can be represented using transverse waves. The compressions can be represented as crests and the rarefactions by troughs.The benefit of drawing all waves as sine waves is that they are easier to draw and the features are clearer.
WAVELENGTH
Wavelength () is the distance from a point on a wave to the corresponding point on an adjacent wave.
It is a scalar quantity with an SI unit of metre (m).
For transverse waves, the wavelength is the distance from the crest of one wave to the crest of the next.
FREQUENCY Frequency (f ) is the number of waves passing a point per second.
It is a scalar quantity with an SI unit of hertz (Hz). 1 hertz is a frequency of 1 oscillation (or cycle) per second 1 Hz 1 cycle s1
AMPLITUDE Amplitude (A) is the maximum distance from the undisturbed position.
It is a scalar quantity with an SI unit of metre (m).
For transverse waves, the amplitude is equal to the distance from the centre to the crest, or half the distance from crest to trough.
For longitudinal waves, amplitude is the maximum distance a particle travels from its rest position when the medium is compressed or rarefied. When a longitudinal wave is represented by a sine wave, the maximum distance a particle travels from its rest position is represented by the height of the crest.
