PhysicsLAB: Mirror Symmetry

PURPOSE

There are many examples of symmetry in nature. Symmetry also occurs often in physics principles and laws (i.e. laws of conservation of momentum and energy). In this lab, we will study the symmetry of reflections in two front surface mirrors and look at some different types of symmetries.

PROCEDURE

Set two front surface mirrors next to each other. Draw the letter M in front of the mirrors. (See Fig. 1) Sketch the image of the letter M as seen in the mirror.
Set up the mirrors with a 90-degree angle between them. Draw the M in front of the mirrors as shown in Fig. II. Sketch the images (3) that you see now.

For the next question, set the mirrors so that you get 4 equal-sized images of the M. Draw a sketch showing the images.

3. What was the angle between your mirrors?

4a. What angle is needed between the mirrors to produce 5 images?

4b. What angle is needed between the mirrors to produce 6 images?

4c. What angle is needed between the mirrors to produce 7 images?

5. Which of the former arrangements of your mirrors produced a set of images which were symmetrical about a vertical axis?