A wave is a means of transferring energy through a medium, without any net movement of that medium.
Transverse wave: A wave where the direction of vibration is perpendicular to the direction in which the wave travels. e.g. light, waves on a rope, water waves.
Longitudinal wave: A wave where the direction of vibration is para;;e; to the direction in which the wave travels. e.g sound, compression waves on a spring.
Key Terms
Frequency: The frequency (f) is the number of cycles completed at any one point per second.
Period: A period of a wave (T) is the time taken to undergo one complete cycle.
Diffraction: Diffraction is the ability of a wave to recover after meeting an obstacle.
Interference
Interference occurs when two waves meet. When this happens, the total displacement will be equal to the algebraic sum of the individual displacements. (All types of waves will undergo interference).
Constructive interference occurs when waves from two sources meet and the amplitude of the resulting wave is greater than the amplitudes of each of the individual waves.
Destructive interference occurs when waves from two sources meet and the amplitude of the resulting wave is less than the amplitude of each individual waves
Coherent waves: two waves that have the same frequency and wavelength.
Interference pattern: When waves from two or more coherent sources meet, the resulting wave pattern formed is called an interference pattern.
Stationary (standing) waves
A stationary wave or a standing wave is produced when two waves of the same frequency and amplitude meet, moving in opposite directions.
The Doppler effect
The Doppler effect is the apparent change in the frequency of the waves due to the motion of the source of the wave or an observer.
