rp9: reflection & refraction

• part 1:

  1. draw a straight line down the centre of the paper using a ruler
  2. use a protractor to draw a line at right angle - normal line
  3. place a glass block so the normal is at the centre of the block
  4. draw around the glass block & turn off lights
  5. use a ray box to direct a ray of light so it hits the block at the normal - incident ray
  6. angle between the incident ray & the normal is the angle of incidence

  
• part 2:

  1. adjust the ray box - there will be a reflected ray & a ray leaving the block - transmitted ray
  2. mark path of the incident ray, reflected ray & transmitted ray with crosses
  3. remove glass block
  4. draw each of the rays & a line to show the path of the transmitted ray
  5. use a protractor to measure the angles

  
• why is light refracted as it crosses from air into glass?

  change in speed
• what is specular reflection?

  reflection from a smooth surface
• what is diffuse reflection?

  reflection from a rough surface
• what happens to wavefronts as they pass the boundary between glass & air?

  • different parts of the wavefront enter the glass at different times
  • speed of light is less in glass
  • one part of the wavefront changes speed before other parts