Transverse & Longitudinal Waves (CIE IGCSE Physics)

• Waves can exist as one of two types:
  • Transverse
  • Longitudinal

Transverse waves

• Transverse waves are defined as:

Waves where the direction of vibration is at right angles to the direction of propagation

• For a transverse wave:
  • The energy transfer is perpendicular to the wave motion
  • They can move in solids, and on the surface of liquids but not in liquids or gases
  • They can move in a vacuum

Transverse wave motion

Transverse waves can be seen in a rope when it is moved quickly up and down

• Examples of waves that can be modelled as transverse are:
  • Electromagnetic waves (such as radiowaves, visible light, X-rays etc)
  • Ripples on the surface of water
  • Seismic S-waves (secondary earthquake waves)

• Longitudinal waves are defined as:

Waves where the direction of vibration is parallel to the direction of propagation

• For a longitudinal wave:
  • The energy transfer is in the same direction as the wave motion
  • They can move in solids, liquids and gases
  • They can not move in a vacuum (since there are no particles)

• The key features of a longitudinal wave are where the points are:
  • Close together, called compressions
  • Spaced apart, called rarefactions

  Longitudinal wave motion

Longitudinal waves can be seen in a slinky spring when it is moved quickly backwards and forwards

• Examples of waves that can be modelled as longitudinal waves are:
  • Sound waves
  • Seismic P-waves (primary earthquake waves)

Difference between transverse and longitudinal waves

Comparing transverse and longitudinal waves