Total Internal Reflection Data Sheet

Part I

  1. Look down the cards when the light is passing through all the cards. Are the holes lined up in a straight line?

  2. What happened when you moved one of the cards a little?

  3. Can we conclude that light travels in a straight line?

  4. Did you see light come all the way through the straw after you bent it?


Part II

  1. Can you conclude that light travels in a straight line inside the test tube?

  2. What is the effect of the powdered milk? Why is it needed?

  3. What do you think would happen if the test tube were ten times longer? Would you still be able to see the zigzag path of the light? Why or why not?

  4. Why would a thin, clear plastic fiber be better than the test tube with water and powdered milk? Would we be able to see the path of the laser light in the plastic?

  5. Were you able to shine the laser inside the test tube at an angle such that a lot of the light came outside the test tube? If so, draw a diagram showing the angle of the laser light path through the test tube.

Part III


  1. What do you observe happens in the stream of water?

  2. Why does the light appear in the water stream?

  3. Can you think of any application of this technique?