Title: Snell’s Law and Total Internal RefractionSubtitle: Lab 24Lab Partners: Amber TelscherDate: 1/03/2016Abstract:This lab dealt with Snell’s Law and Total Internal Reflection. There were two experiments in thislab. The first experiment was called Law of Reflection and it dealt with the investigation of reflecting a laser beam onto a mirror in a particular way and making observations about the results. For the second experiment regarding Snell’s Law, we were in charge of verifying the use of Snell’s Law using a refraction cell and a laser. During this lab, we witnessed total internal reflection and the effects of a laser traveling through different mediums such as water and air. During this report, you will see the exploration of incidence angles and refractive angles and the correlation between the two using Snell’s Law. The big trend worth noting that was observed in Experiment 1 is that there seems to be an inversely proportional relationship between the incidence angle and the reflective angle seen when the laser was shown at the reflective mirror asdescribed in the procedure. Lastly, the main observation seen in experiment two, was the positivecorrelation between the plotting of sin ( i) vs. sin ( r).ɵ ɵIntroduction and Background:This experiment has multiple factors to it; the main factor in consideration is Snell’s Law and Total Internal Reflection when dealing with a minimum of two mediums. Some of the factors used to help set the foundation to help us learn about Snell’s Law, is the fact that subatomic particles actually interact and will release and absorb energy in the form of electromagnetic radiation, which travels through space in the form of electromagnetic waves. This leads to the electromagnetic spectrum, which includes everything from radio waves to gamma rays. The portion that we see as humans is only a small part of the spectrum, and it is known as the visible light spectrum, also called the color spectrum, which is in the range of 400-750 nm wavelengths. Although this bit of information isn’t as important to help us understand Snell’s Law, I thought that it was worth noting that what you actually see is a result of different wavelengths of light being reflected from a material. When looking at what Reflection means, it is the occurrence of waves bouncing off of a material. With reflection, the angle of incidence is actually equivalent ofthe angle of reflection. Total internal reflection occurs when an incident wave traveling at an angle enters a medium and no refraction occurs, leading to a complete reflection. The critical angle of an incident light wave is the largest angle that a wave can enter a medium and still refract. Refraction occurs when a beam of light transmits from one medium to another. Snell’s Law shows us in an equation the amount of refraction that is happening when a ray travels from one medium to another. This equation is n1sin ( i)=n2sin ( r), where n1 is the index of ɵ ɵrefraction of the material for the incidence medium and n2 is the index of refraction of the refracting medium, and where i the angle of incidence to the normal and r is the angle of ɵ ɵrefraction to the normal of that location of refraction. So during this lab, we were trying todetermine the relationship between the incident ray and reflected angle when experimenting for Law of internal reflection to calculate the critical angle.Method:To begin with, this lab was conducted on a kitchen table as the counter surface for the lab. The lab setting was a control for this experiment due to its unchanging nature. Another control duringthis lab is the use of the same laser beam was used throughout the experiment. A few variables that were changed during this experiment were the use of a plane mirror for the first lab to be used to demonstrate reflection, while a refraction cell holding water was used for the second experiment within the lab in order to test the refraction angles that would occur when a laser was pointed through the curved side of the refraction cell to be refracted out on the other side of the cell in the opposite direction in which the laser was being pointed. Materials that were used for the Law of Reflection experiment, include; a laser pointer, a mirror support, a plane mirror, a protractor, and a sheet of paper. The procedure for this part of Lab 24 had us place a sheet of paper onto the table and lay a protractor on it. After we were instructed to place the bottom left corner of the plane mirror into the mirror support, we were further instructed to rest the bottom right side of the mirror on top of the protractor in line with the origin mark of the protractor. Withthe reflective side facing the angles, we developed a technique to shine the laser from particular angle marks going in 5 increments towards the origin to observe how the light was reflected. Following you can see the general set up in the picture included to demonstrate what was happening during experiment 1 in order to record the values for the reflected angles.The procedure for experiment 2 over Snell’s Law required the following materials; refraction cell, 2 protractors, laser pointer, masking tape, water, and a sheet of paper. The first step of the procedure had us fill the refraction cell ¾ full of water and remove any bubbles present. The nextstep entailed us laying 2 protractors down centering the over their origins and securing them down with masking tape to create a complete 360⁰ protractor. After these steps were completed, we were instructed to set the refraction cell directed centering in the middle of the protractor. Thelaser into the curved side of the refraction cell, aiming at the middle of the flat side of the cell to witness the observed refraction angle that occurred when the laser was shown into the water medium and was refracted back out into the air. We shined the laser in 5 increments into the water, all the while recording the associated refraction angle for each of the incidence angles listed in Table 3 of experiment 2. Results:Experiment 1: Law of reflection had a table for us to fill out in regards to the Laser and Mirror Reflection Data. The relationship between the incident and reflected angle seemed to be inversely proportional. Meaning, as the incident angle increased, the reflected angle decreased. This is not true for all materials; due to each material has its own index of refraction.For the results of Experiment 2 in regards