Light & Sound Waves (Edexcel IGCSE Physics)

Light

Spec point — 3.14 · know that light waves are transverse waves and that they can be reflected and refracted

• Visible light is a part of the Electromagnetic spectrum which means it is a transverse wave

  • This is explained in Transverse & longitudinal waves

Representing a transverse wave

Light waves are transverse: the particles vibrate in a perpendicular direction to the energy transfer

• Light can undergo:

  • Reflection
  • Refraction

Sound

Spec point — 3.23 · know that sound waves are longitudinal waves which can be reflected and refracted

• Sound waves are longitudinal waves

  • This is explained in Transverse & longitudinal waves

• Longitudinal waves are usually drawn as several lines to show that the wave is moving parallel to the direction of energy transfer

  • Drawing the lines closer together represents the compressions
  • Drawing the lines further apart represents the rarefactions

Representing a longitudinal wave

Longitudinal waves are represented as sets of lines with rarefactions and compressions

• Sound can also undergo:

  • Reflection
  • Refraction

• The reflection of a sound wave is called an echo