Refraction

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

  Refraction
• Why do waves travel at different speeds in different materials?

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

  Higher density slows down the wave
• What happens to a light wave when it travels from air into glass?

  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 will be refracted and change direction
• What do we call the ray that is bent as it enters a more dense medium?

  Refracted ray
• How should the refracted ray be drawn in a ray diagram?

  About halfway towards the normal
• What happens to the light ray when it exits the glass back into air?

  It speeds up and bends away from the normal
• What do we call the ray that emerges from the glass into the air?

  Emergent ray
• What angles need to be included in a ray diagram for refraction?

  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?

  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 are the steps to draw a ray diagram for refraction through glass?

  1. Draw the normal at the point of incidence.
  2. Draw the incident ray towards the glass.
  3. Draw the refracted ray bending towards the normal.
  4. Draw the normal again at the exit point.
  5. Draw the emergent ray bending away from the normal.
  6. Label the angles of incidence and refraction.
• What is the relationship between wave speed, frequency, and wavelength?

  • Wave speed = frequency × wavelength
  • Frequency remains constant during refraction
  • Wavelength changes with speed
• How does white light behave when passed through a triangular prism?

  • White light contains all visible wavelengths
  • Different colors bend to different degrees
  • Results in a spectrum or rainbow effect