# 6.1.2 Describing Wave Motion

### Describing Wave Motion

• When describing wave motion, there are several terms which are important to know, including:
• Amplitude
• Wavelength
• Frequency
• Period

#### Amplitude

• Amplitude is defined as:

The distance from the undisturbed position to the peak or trough of a wave

• It is given the symbol A and is measured in metres (m)
• Amplitude is the maximum or minimum displacement from the undisturbed position

#### Wavelength

• Wavelength is defined as

The distance from one point on the wave to the same point on the next wave.

• In a transverse wave:
• The wavelength can be measured from one peak to the next peak
• In a longitudinal wave
• The wavelength can be measured from the centre of one compression to the centre of the next
• The wavelength is given the symbol λ (lambda) and is measured in metres (m)
• The distance along a wave is typically put on the x-axis of a wave diagram Diagram showing the amplitude and wavelength of a wave

#### Frequency

• Frequency is defined as:

The number of waves passing a point in a second

• Frequency is given the symbol f and is measured in Hertz (Hz)

#### Time Period

• The time period of a wave is defined as:

The time taken for a single wave to pass a point

• The time period is given the symbol T and is measured in seconds (s)  ### Author: Katie

Katie has always been passionate about the sciences, and completed a degree in Astrophysics at Sheffield University. She decided that she wanted to inspire other young people, so moved to Bristol to complete a PGCE in Secondary Science. She particularly loves creating fun and absorbing materials to help students achieve their exam potential.
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