Waves: Common features

Waves are oscillations that transport energy from one place to another without transferring matter.

They can be classified into mechanical waves (requiring a medium to propagate, such as sound waves) and electromagnetic waves (can propagate in vacuum, like light waves).

Waves exhibit common properties such as amplitude, wavelength, frequency, and speed, understanding each is important to comprehend the wave behaviour.

Amplitude is the maximum displacement of a point on the wave from its rest position.

It determines the loudness in sound waves and brightness in light waves.

It’s usually measured in metres (m).

Wavelength is the distance over which the shape of the wave repeats.

It can be measured as the distance between successive crests or between successive troughs.

It affects the colour of light, and the pitch of sound.

Given usually in metres (m) or nanometres (nm) for light waves.

Frequency refers to the number of wave cycles or oscillations that pass a given point in one second.

It is inversely proportional to the wavelength.

It affects aspects such as the pitch of a sound (higher frequency, higher pitch) or the colour of light (higher frequency, more towards violet end).

Measured in hertz (Hz)

Wave speed is the speed at which the wave moves in relation to the medium.

It is calculated by the formula: Speed = Frequency x Wavelength.

Unlike frequency and wavelength, the speed of a wave is determined by the type of wave and the nature of the medium, not by its frequency or amplitude.

Waves can undergo several types of interactions like reflection (bouncing off a surface), refraction (bending as it passes from one medium to another), diffraction (bending round obstacles) and interference (where multiple waves meet).