5.3 - Refraction

• What is refraction of light waves?

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

  Different materials have different densities
• What happens to a wave when it travels from air into glass?

  It slows down and bends towards the normal
• How does the angle of incidence affect the direction of a wave at a boundary?

  It determines how much the wave bends
• What is the normal in the context of refraction?

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

  It gets refracted and changes direction
• How do you draw a ray diagram for light refraction?

  Draw the normal and incident ray, then refracted ray
• Refraction refers to the change in direction of a wave, as it passes from one medium to another, and is caused by its change in speed.
• What is the emergent ray in a ray diagram?

  The ray that exits the second medium
• What does the wave speed equation state?

  Wave speed equals frequency times wavelength
• What happens to the frequency of a wave during refraction?

  The frequency always stays the same
• If the speed of a wave increases, what happens to the wavelength?

  The wavelength must also increase
• How do different wavelengths of light behave in a prism?

  They are refracted by different amounts
• What is the process of light refraction through a triangular prism?

  1. White light enters the prism.
  2. Different wavelengths bend at different angles.
  3. Colors spread out, forming a rainbow.
• What is the result of passing white light through a triangular prism?

  It spreads out into a rainbow of colors
• What are the key concepts of light refraction?

  • Refraction changes wave direction
  • Speed varies with medium density
  • Normal line is perpendicular to surface
  • Wavelength changes, frequency remains constant
• Light travels more ________ in a more dense material.

  slowly
• Light travelling from a less dense material, into a more dense material, will bend ________ the normal.

  towards
• Point of incidence: C

  Refracted ray: E

  Incident ray: A

  Angle of incidence: B

  Emergent ray: G

  Angle of refraction: D

  Normal: F

  
• When a wave travels into a more dense medium, the wave speed decreases.

  The frequency of the wave:

  Stays the same
• When a wave travels into a more dense medium, the wave speed decreases.

  The wavelength of the wave:

  Decreases
• They have all refracted at different angles