1

Part 1: Reflection/Refraction with Pins

Reflection:

Outline the front of your mirror

Using two pins place them to the left side of the middle of the mirror (see Figure 20.1).

Then look from the right side of the mirror and line up two pins images with each other and place a pin on the right side so that the pin blocks out the image of the two pins. Then place another pin behind that pin that blocks out the pin in front of it and the two images. Circle the holes in your paper and connect the dots and draw it to the front side of the mirror.

Draw a normal line where the two lines meet the mirror. Using a protractor measure and record the angles of incidence and reflection (see Figure 20.2).

Trace the reflected rays.

Using a protractor measure the angle of incidence and reflection.

Now rotate the mirror to the right about the normal line. Then place two more pins to the right and draw that reflected ray. Measure the reflected angle from the previous normal line. Record angles (see Figure 20.3).

Refraction:

Trace the outline of your block then place two pins at an angle to the block (see Figure 21.1).

Part 1: Refraction Cont’d

Then look through the block from the other side and line up two pins with the pins on the other side of the block (see Figure 21.2).

Connect the lines to the block. Draw a normal line on each side of the block. Connect the lines across the block and using a protractor measure the angles of incidence and refraction.

4. Calculate the index of refraction for the block.

5. What is the block made out of? Do a % error.

6. Calculate the speed of light in the block.

List your answers to questions # 1 – 6 beside appropriate diagrams. In order to receive full credit, remember to show your work including formulas and substitutions with units.

Part 2: Reflection/Refraction

Additional Questions for Lab: Show all work and box all answers to receive full credit

  1. Could you ever have a situation where light travels faster than the speed of light in a vacuum? (Hint: Use the index of refraction formula to guide your thinking.)
  1. Describe the relationship between refraction angle, θR, speed of light in a medium, v, and index of refraction, n.
  1. Draw a scaled refraction diagram of light traveling through air incident on flint glass at an angle of 90˚ to the surface of the boundary. (Verify results via Snell’s Law.)
  1. Draw a scaled refraction diagram of light traveling through corn oil incident on glycerol at an angle 60˚ to the normal. (Verify via Snell’s Law/Identify quick solve logic, Hint: use question #2 as a starting pt.)
  1. Determine the critical angle, θc, for Zircon (a guy’s best friend). Take medium two, n2, as air.
  1. Determine the minimum angle necessary to produce a total internal reflection case for the previous problem. Illustrate the ray diagram.
  1. Yellow light, f = 5.09 x 1014 Hz, travels from water into air.

(a)With what speed does light travel through air?

(b)Does the frequency value change for the yellow light as it moves from one medium to the next? Explain.

(c)Determine the individual wavelengths of the light in these two media.