1. Waves are produced by vibrating systems.
2. Waves transfer energy. Waves that travel through a medium transfer energy without transferring matter.
3. In transverse waves, the direction of waves propagation is perpendicular to the direction of vibration of the particles.
Example: water waves, light waves and electromagnetic waves.
4. In longitudinal waves, the direction of wave propagation is parallel to the direction of vibration of the particles.
Longitudinal waves need a medium to propagate. This type of waves cannot propagate through a vacuum.
Example: a sound wave.
5. A wavefront is an imaginary line representing all parts of a wave in which particles are vibrating in the same phase and have the same distance from the source.
The direction of propagation of waves is always perpendicular to the wavefront.
6. Amplitude, a, is the maximum displacement from the equilibrium position.
7. Period, T, is the time required to make one complete oscillation.
8. Frequency, f, is the number of complete oscillations made in one second.
9. Wavelength, is defined as the distance between two consecutive points that are in phase.
( i ) For a transverse wave, wavelength can be measured as the distance from one crest and also the distance from one trough to the next trough.
(ii ) For a longitudinal wave, wavelength can be measured as the distance between
two consecutive compressions or two consecutive rarefactions.