Wave Properties (Wavelength, period, speed) - SS1 Physics Lesson Note
Three fundamental properties of waves are wavelength, period, and speed.
1. Wavelength: Wavelength is the distance between two consecutive points in a wave that is in the same phase, such as two crests or two troughs. It is typically represented by the symbol λ (lambda) and is measured in metres (m) or other appropriate units. Wavelength determines the spatial extent of a wave, and different types of waves have different wavelength ranges. For example, visible light waves have wavelengths ranging from approximately 400 to 700 nanometers.
2. Period: Period is the time taken for one complete cycle of a wave to pass a given point. It is represented by the symbol T and is measured in seconds (s) or other appropriate units. The period is the reciprocal of the frequency, which is the number of complete cycles of a wave that occur per unit of time. Mathematically, period (T) is related to frequency (f) as T = 1/f. The period of a wave determines its temporal characteristics, such as the time between consecutive crests or troughs.
3. Speed: The speed of a wave refers to how fast the wave propagates through a medium. It is represented by the symbol v and is measured in metres per second (m/s) or other appropriate units. The speed of a wave depends on the properties of the medium through which it travels. In a vacuum, electromagnetic waves, such as light, travel at the speed of light, denoted as c ≈ 3 x 108 m/s. In other media, such as air, water, or solids, the speed of waves can vary depending on the properties of the medium.
These wave properties are interconnected through mathematical relationships. The speed of a wave is related to its wavelength and period by the equation v = λ/T. This equation indicates that waves with longer wavelengths have lower frequencies and longer periods, while waves with
shorter wavelengths have higher frequencies and shorter periods.
Understanding wave properties is crucial in various scientific fields, including physics, acoustics, optics, and communication. These properties help describe and analyse the behaviour of waves, including phenomena such as interference, diffraction, and refraction. They also play a vital role in the design and optimization of technologies that rely on wave propagation, such as telecommunications systems, medical imaging devices, and sound engineering applications.