Objective

The purpose of this experiment is to prove the laws of reflection and refraction, and to determine the angle of the total internal reflection and the index of refraction in the experiment.

Theory

The theory being experimented in this procedure is that of Willebrord Snell. From his theory we understand that the incident ray, the normal line and the refracted ray all lie on the same plane. We also understand that the relationship is defined in a ratio with the following equation;

Which means that the ratio of the sine of the angle of incidence to the sine of the angle of refraction, I equal to the ratio of the speed of light in the original medium and the speed of light in the refracting medium.

Procedure

We set up the optics track, light source and the ray table. We then aligned the flat side of the mirror with the ray of light from the light source. We rotated the ray table in increments of 10 ̊. The first set were done going clockwise. Once done we then did the same thing but going counterclockwise. This gave us the Angles of Reflection. FromThe two Angles of Reflection we were able to calculate the average Angles of Reflection, listed in Table 1. For the Law of Refraction, we replaced the mirror with a Acrylic cylindrical lens. We rotated the ray table clockwise by increments of 10̊ again. We repeated the same measurements but instead with counterclockwise angles. From the two angles of refraction we were able to calculate the average angles of refraction. Finally, we aligned the flat side of the lens so that incoming light ray struck the cylindrical surface. We rotated the ray table until the refracted ray disappeared completely and only the reflected ray was visible. This is the angle of incidence. This gave us our angle of incidence theoretical value. From this we were also able to calculate the angle of refraction.