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?

  The higher the density of the material, the slower the wave will travel through it
• 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?

  It is the dashed line perpendicular to the surface at the point of incidence
• What occurs when a wave hits the boundary between two materials at an angle?

  It will be refracted, changing its direction
• In a ray diagram, what is the first step when drawing the transmission of a ray through glass?

  Draw the normal line perpendicular to the glass surface at the point of incidence
• What happens to the direction of a light ray when it enters a more dense medium?

  It bends towards the normal
• What is the emergent ray in a ray diagram?

  It is the ray that exits the medium after refraction
• What must be added to a ray diagram to complete it?

  The angle of incidence and the angle of refraction
• According to the wave speed equation, what does wave speed equal?

  Wave speed equals frequency times wavelength
• What happens to the frequency of a wave as it passes from one medium to another?

  The frequency always stays the same
• What changes when the speed of a wave increases as it passes into a different medium?

  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, spreading out like a rainbow
• What are the key steps to draw a ray diagram for refraction through glass?

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

  • Wave speed = frequency × wavelength
  • If wave speed increases, wavelength increases (frequency remains constant).
  • If wave speed decreases, wavelength decreases (frequency remains constant).