Total Internal Reflection Lab
Purpose
Investigate total internal reflection.
Materials
cardboard, 3 pins, ruler and acrylic half circle block
Directions
- Place the acrylic block in outlined area on the 360-degree protractor on your paper.
- Place one pin next to the flat side of the acrylic block at Point 1 (P1).
- Place a second pin, P2, at 70 degrees.
- Place your eye, eye level with the sheet of paper.
- While looking through the curved side, move your line of sight either to the right or left until image of the pin seen through the glass lines up with the pin above the glass. Place a third pin, P3 at this point.
- Record the angle of pin P3.
- Move pin P2 to 60 degrees.
- While looking through the curved side, move your line of sight either to the right or left until image of the pin seen through the glass lines up with the pin above the glass. Place a third pin, P3 at this point.
- Record the angle of pin P3.
- Continue decreasing the LARGEST angle of pin P2 until you are no longer able to align the image seen through the glass with the pin above the glass. This angle is called the CRITICAL ANLGE.
- Record the critical angle