Refraction of Waves

• What is the main topic of the video?

  Refraction of waves
• What is refraction in the context of waves?

  • Change of direction of waves
  • Occurs when waves change speed
  • Happens when moving from one medium to another
• What should higher tier students be able to use to explain refraction?

  Wavefront diagrams
• Why do waves change direction when they change speed?

  Because they change speed moving from one medium to another
• How can a ray diagram illustrate refraction?

  • Shows a ray of light entering a new medium
  • Illustrates the change in direction as light slows down or speeds up
  • Includes a normal line at right angles to the surface
• What happens to light waves when they pass from air into glass?

  The velocity of light decreases
• What is the effect of light waves slowing down when entering glass?

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

  The velocity of light increases
• What occurs when waves speed up as they move from glass to air?

  They bend away from the normal
• Under what condition do waves not change direction when entering or leaving a medium?

  When they enter or leave at right angles to the surface
• What is a wavefront?

  • An imaginary line connecting points of identical phase in a wave
  • Can connect peaks or troughs of waves
  • Helps visualize multiple waves moving together
• How does a wavefront diagram help explain refraction?

  It shows how parts of the wavefront slow down and change direction
• What occurs when the whole wavefront slows down at the same time?

  • Waves do not change direction
  • The wavefront remains aligned
  • Refraction does not occur
• What happens to the wavelength of waves as they enter a denser medium?

  The wavelength gets smaller