Color of Stars Properties of Dust Super Gelatin Telescope Allocation Committee Astro-Madness Hot Air Spectroscope Mirror, Mirror

Subject: Physical Science
Grade Level: 9-12

Materials You Will Need
For each student group:

• Laser pointer
  
• 1/2 inch binder clip
  
• 8.5 x 11 inch graph paper
  
• protractor
  
• ruler
  
• 3 front silvered mirrors
  

Guides and Worksheets
Download, print and photocopy these lesson documents for your class.

Teacher lesson plan 64K
StarDate script for the activity 52K
Student activity sheet 32K

Overview
In this experiment, students construct an equilateral triangle using graph paper, pencil, protractor and a ruler. They also make a "laser triangle" using a laser pointer and front-silvered mirrors. Students can use the geometric properties of an equilateral triangle combined with their understanding of the Law of Reflection to decide how to place the mirrors at each vertex so that the "laser triangle" fits their equilateral triangle.

Warning: Students should exercise extreme caution when using the laser pointers, since direct laser light entering the eye could cause retina damage.

What Students Do
Students produce an equilateral triangle, ray-tracing of a retro-reflector, and build a retro-reflector using front-silvered mirrors.

*TEKS are Texas Essential Knowledge and Skills. For more information, visit http://www.tea.state.tx.us/teks/.