Revise GCSE Physics


Question:What are the correct definitions for Amplitude, wavelength, frequency and speed of a wave?

See the diagrams for clarification.

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The Amplitude of a wave is the height of the wave; from the undisturbed point to the peak. It is a measure of the energy carried by the wave because the greater the disturbance the more energy required.

The Wavelength of a wave is the distance from any point on a wave to the corresponding point on the next wave, in metres.

This could be the peak to peak distance or the trough to trough distance or from the undisturbed point to the second undisturbed point (not the next).


The Frequency of the wave is the number of waves produced per second; or the number of waves passing a point per second (this must be the same number). The frequency is also called the number of cycles per second or the number of oscillations per second. The unit of frequency is the Hertz (Hz). 1 Hz means one wave per second.

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The Speed of a wave is the distance in metres travelled by the wave in one second. Unit: meters per second (m/s).