refraction

• What happens to light as it passes through water?

  It appears to change direction
• Why do waves change direction when they change speed?

  Because they move from one medium to another
• How can you illustrate refraction using a ray diagram?

  By showing light entering a glass block
• What happens to the velocity of light when it passes from air into glass?

  It decreases
• What does the normal line 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 to light waves when they pass from glass back to air?

  They speed up and bend away from the normal
• What can cause the image of an object to appear shifted?

  Refraction of light waves
• When does refraction not occur?

  When waves enter at right angles
• 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 causes waves to change direction towards the normal?

  When parts of the wavefront slow down
• What happens to wavefronts when they approach along the normal?

  They do not change direction
• What are the key concepts of refraction?

  • Waves change direction when speed changes
  • Light slows down in denser media
  • Waves bend towards the normal when slowing down
  • Waves bend away from the normal when speeding up
  • No change in direction 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