Wave Characteristics (Amplitude, Frequency, Wavelength) - SS2 Physics Lesson Note

Wave characteristics, such as amplitude, frequency, and wavelength, play a crucial role in understanding the behaviour and properties of waves.

Amplitude:

Amplitude refers to the maximum displacement or distance that a wave moves from its equilibrium position. In a transverse wave (e.g., water waves or electromagnetic waves), the amplitude represents the maximum height or distance between the crest (highest point) and the trough (lowest point) of the wave. In a longitudinal wave (e.g., sound waves), the amplitude represents the maximum compression or rarefaction of the medium particles. The amplitude determines the energy carried by the wave, with larger amplitudes indicating higher energy.

Frequency:

Frequency is the number of complete cycles or oscillations of a wave that occur in a given time period. It is measured in Hertz (Hz), where 1 Hz represents one cycle per second. The frequency determines the pitch of a sound wave or the colour of light in the case of electromagnetic waves. Higher frequencies correspond to shorter time periods between wave cycles, resulting in higher pitch or higher energy electromagnetic radiation.

Wavelength:

Wavelength is the distance between two consecutive points in a wave that is in phase, i.e., two points that are in the same position within their respective cycles. It is usually represented by the Greek letter lambda (λ).  In a transverse wave, the wavelength is measured as the distance between two adjacent crests or troughs. In a longitudinal wave, the wavelength is measured as the distance between two adjacent compressions or rarefactions. Wavelength and frequency are inversely related: as the frequency increases, the wavelength decreases, and vice versa. This relationship is described by the equation: speed = frequency x wavelength.

The amplitude, frequency, and wavelength of a wave are interconnected and define its characteristics. For example:

-       In sound waves, higher amplitudes result in louder sounds, while higher frequencies correspond to higher-pitched sounds.

-       In electromagnetic waves, larger amplitudes represent brighter or more intense light, while different wavelengths correspond to different colours of light.

Understanding these wave characteristics is essential in various fields, including physics, engineering, telecommunications, and music. They allow us to analyse and manipulate waves to achieve specific outcomes, such as optimising signal transmission, creating desired sounds, or studying the behaviour of light.