Refraction

• What is the phenomenon called when light waves change direction as they pass from one medium to another?

  Refraction
• What happens to light waves when they travel from air into glass?

  They slow down and change direction
• What do you need to know to understand refraction?

  Waves travel at different speeds in materials
• Why do waves travel at different speeds in different mediums?

  Different mediums have different densities
• How does the density of a material affect the speed of electromagnetic waves like light?

  The higher the density, the slower the wave travels
• What happens to a wave traveling from a less dense medium to a more dense medium?

  It slows down and bends towards the normal
• What is the normal line in the context of refraction?

  A dashed line perpendicular to the surface
• What occurs when a wave hits the boundary at an angle?

  It is refracted and changes direction
• What is the first step in drawing a ray diagram for refraction?

  Draw the normal at the point of incidence
• What happens to the incident ray when it enters a more dense medium?

  It bends towards the normal
• What do you call the ray that emerges from the glass into the air?

  Emergent ray
• What must be added to the ray diagram to complete it?

  The angle of incidence and angle of refraction
• What does the wave speed equation state?

  Wave speed equals frequency times wavelength
• What remains constant when a wave passes from one medium to another?

  The frequency of the wave
• What happens to the wavelength when the speed of a wave increases?

  The wavelength must increase as well
• How do different wavelengths of light behave when passing through a triangular prism?

  They are refracted by different amounts
• What is the process of refraction in detail?

  • Light waves change direction at medium boundaries
  • Waves travel at different speeds in different materials
  • Higher density slows down light waves
  • Bending occurs towards the normal in denser mediums
  • Bending occurs away from the normal in less dense mediums
• How to draw a ray diagram for refraction?

  1. Draw the normal at the point of incidence
  2. Draw the incident ray towards the normal
  3. Determine the direction of bending
  4. Draw the refracted ray into the new medium
  5. Repeat for the emergent ray
  6. Label angles of incidence and refraction
• What are the effects of changing mediums on wave properties?

  • Speed changes with medium density
  • Frequency remains constant
  • Wavelength changes with speed
  • Different wavelengths refract differently