ENERGY

The Use of Waves and Universe Expansion – Amplitude, wavelength, frequency and speed

The Use of Waves and Universe Expansion – Amplitude, wavelength, frequency and speed

The nature of a wave can be described using three main terms:

  • Physics GCSE science revision- Energy– amplitude
  • – wavelength
  • – frequency

When a wave travels it sets up patterns of disturbance. Its undisturbed position is a set, straight line. The maximum disturbance from this line is known as its amplitude. (Note that the amplitude isn’t the length of a wave from top to bottom).

Physics GCSE science revision- EnergyThe wavelength is the distance between two waves. It’s important that the point measured from one wave to the other is in the same place. One of the easiest points to measure is from the crest to crest.

The frequency of a wave is how many waves are produced each second from a source or that pass a particular point each second.

Frequency is measured in hertz (Hz). However, if a wave has a particularly high frequency it’s more common to use kilohertz (kHz), megahertz (MHz) or gigahertz (GHz). For example, radio waves have a frequency of around 100 MHz while a lot of wireless networks function at 2.4 GHz.

——————————————————

Wave speed

The speed of a wave can be calculated using the following equation:

v = f x ?

  • v is the wave speed in metres per second (m/s)
  • f is the frequency in hertz (Hz)
  • ? (lamda) is the wavelength in metres (m)

In your exam you could be given any two values and need to work out the third. An easy way to work about what you should do to what is to use the triangle method.

So:

  • v = f x ?
  • f = v / ?
  • ? = v / f