Edexcel IGCSE Physics 复习笔记 3.2.1 Light & Sound Waves

• Visible light is a part of the electromagnetic spectrum which means it is a transverse wave
  • This means the direction the light particles vibrate is perpendicular to the direction of the energy transfer

   

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

• Light can undergo:
  • Reflection
  • Refraction

   

• All waves in the electromagnetic spectrum can be reflected and refracted

• Sound waves are vibrations of air molecules
• When a sound wave comes into contact with a solid those vibrations can be transferred to the solid
  • For example, sound waves can cause a drinking glass to vibrate
  • If the glass vibrates too much the movement causes the glass to shatter

   

• Sound waves are longitudinal waves
  • This means the direction the light particles vibrate is parallel to the direction of the energy transfer

   

• Hence, it consists of:
  • Compressions - regions of higher density
  • Rarefactions - regions of lower density

   

Sound waves are longitudinal: the particles vibrate in the same direction as the energy transfer

• Sound can also undergo:
  • Reflection
  • Refraction

   

• The reflection of a sound wave is called an echo