Refraction of waves

• What is the main topic of the video?

  Refraction of waves
• What should students be able to construct by the end of the video?

  Ray diagrams showing refraction
• What additional skill should higher tier students learn?

  Use wavefront diagrams to explain refraction
• What happens to light as it passes through water?

  It appears to change direction
• Why do waves change direction when moving from one medium to another?

  Because they change speed
• How can refraction be illustrated?

  With a ray diagram
• What happens to the velocity of light when it passes from air into glass?

  It decreases
• What does the normal represent in a ray diagram?

  A line at right angles to the surface
• What occurs when waves slow down as they enter a denser medium?

  They bend towards the normal
• What happens when light waves pass from glass back to air?

  They speed up and bend away from the normal
• What is a key fact about refraction?

  Waves can change direction when speed changes
• Under what condition do waves not change direction when entering a medium?

  When entering at right angles to the surface
• What is a wavefront?

  An imaginary line connecting points in waves
• How do wavefronts help visualize waves?

  They connect identical points in waves
• What happens to wavefronts when they enter a denser medium?

  They get closer together and slow down
• What is the effect of wavelength on wave direction during refraction?

  Shorter wavelength causes bending towards normal
• What happens to wavefronts when they approach along the normal?

  They slow down without changing direction
• What are the key concepts of refraction?

  • Waves change direction when speed changes
  • Light slows down in denser mediums
  • Waves bend towards the normal when slowing down
  • Waves bend away from the normal when speeding up
  • No direction change occurs at right angles
• What are the differences between ray diagrams and wavefront diagrams?

  • Ray diagrams show light paths
  • Wavefront diagrams show wave behavior
  • Ray diagrams illustrate refraction visually
  • Wavefront diagrams explain speed changes