Wave: A wave is a pattern of disturbance which travels through a medium due to repeated vibrations of the particles of the medium.
The disturbance is handed over from one particle to the next.
Sound is pictorially represented by a continuous succession of peaks and valleys.
Wave Motion: The motion of the disturbance is called wave motion.
TYPES OF WAVES
Waves are of two types:
Longitudinal waves
Transverse waves
LONGITUDINAL WAVES
These are the waves in which the particles of the medium vibrate along the direction of wave motion.
The waves which travel along a spring (or slinky) it is pushed and pulled at one end, are longitudinal waves.
A longitudinal wave consists of two attributes travelling through a medium:
Compressions and
Rarefactions
Compression:
It is a part of longitudinal wave.
Compression is a region of high pressure.
In compression, particles of the medium are closer to one another than they normally are.
There is a momentary reduction in volume of the medium during compression.
Rarefaction: It is a part of longitudinal wave. Rarefaction is a region of low pressure. In rarefaction the particles of the medium are farther apart than normal, and there is a momentary increase in the volume of the medium.
TRANSVERSE WAVES
In transverse waves, the particles of the medium vibrate perpendicular to the direction of wave motion.
Transverse waves can be produced only in solids and liquids but not in gases.
A transverse wave travels horizontally in a medium, the particles of the medium vibrate up and down in the vertical direction.
A transverse wave consists of
Crests and
Troughs
Crest: Crest is the ‘elevation’ in a transverse wave.
Trough: Trough is the ‘depression’ in a transverse wave.
