We have already learnt that Sound waves cause Compression and Rarefaction
Particles of medium (air particles) are tightly packed, hence there is more density and more pressure
Particles of medium (air particles) are loosely packed, hence they have less density and less pressure
Plotting them on Graph
We get peaks and trough as follows
The peak represents region of highest compression. It is called the crest.
The valley represents region of rarefaction. It is called the trough.
What is Wavelength of Sound Wave
The distance between any two consecutive compressions or rarefactions is called wavelength.
SI unit of wavelength is metre (m)
It is denoted by lambda. (λ)
Wavelength is the distance between
2 consecutive compressions (2 Crests)
2 consecutive Rarefactions (2 Troughs)
It is denoted by lamda (λ)
Its SI Unit is meter