7.1.5 Transverse & Longitudinal Waves

• In mechanical waves, particles oscillate about fixed points
• The direction of oscillations with regards to the direction of wave travel determine what type of wave it is

Transverse waves

• A transverse wave is one where the particles oscillate perpendicular to the direction of the wave travel (and energy transfer)
• Transverse waves show areas of crests (peaks) and troughs

Diagram of a transverse wave

• Examples of transverse waves are:
  • Electromagnetic waves e.g. radio, visible light, UV
  • Vibrations on a guitar string

• These can be shown on a rope
• Transverse waves can be polarised

Longitudinal waves

• A longitudinal wave is one where the particles oscillate parallel to the direction of the wave travel (and energy transfer)
• Longitudinal waves show areas of compressions and rarefactions

Diagram of a longitudinal wave

• Examples of longitudinal waves are:
  • Sound waves
  • Ultrasound waves

• These can be shown on a slinky spring
• Longitudinal waves cannot be polarised
• You will have learned how to analyse the properties of a wave, such as amplitude and wavelength, in “General Wave Properties”
• The diagram below shows the equivalent of a wavelength on a longitudinal wave

Wavelength shown on a longitudinal wave

ANSWER:   A