Lab 7 refraction Kassidy Schanzlin physics 222

Kassidy Schanzlin Kschanzl@vols.utk.edu Physics 222 10/25/2023 Lab 7: Refraction Purpose: The purpose of this experiment is to understand and practice using Snell’s Law while being able to visualize specific angles and refractions through data and visual aids. In addition, to compare the relationship between light and different material to see the refraction. Exploration 1: A)  Plot R versus theta. Paste your graph into your log. Compare to the graph above.  Discuss your result. My graph in comparison to the one shown in the example is very similar as the exponential growth occurs after a 45-degree angle is formed/achieved. o Is the laser light p-polarized, s-polarized, or unpolarized. What do your results suggest?  S-Polarized as it is the same trendline from the Module example.  Calculate Sini (.6) and sent ( .3) Remember that Excel functions require the angles to be in radians.  Plot Sini versus sent. o What does the plot look like? Linear Slope. The calculated slope was .7472.

o Use the trendline to find the slope. Paste the graph with trendline into your log. o What value do you obtain for the slope? Y= .7472 o Given Snell's law, what value do you expect for the slope? Discuss!  Given Snell’s Law we can comprehend that the slope should be equal to the inverse of the index of the refraction of water. The value expected is similar. (b) Design experiments to determine the index of refraction of mystery materials A and B.  Describe your procedure and discuss why you decided to proceed this way. What are your results for n ab and n ab ? o I used the same procedure as the experimental design because I did not want to do something incorrectly. When I refracted the laser through the mystery material A and B and measured my results. I concluded that the initial and refracted angles are to be. Na = .2417 Nb= 1.39 unsingle sin/sir to calculate the index. (c) Design and describe a setup that has the refracted ray bend away from the normal? When you point the laser through the glass into the water it causes the laser goes through but refracts away as is passing through the material. For it to bend away from the normal you need to have a medium with a higher refractive index on top and a medium with a lower refractive index on the bottom, so I used 1.50 glass on top and n=1 of air on the bottom.

o The Triangle did the best because the white light seperated into differnet colors. The triangles refracts the laser well.  Try to arrange a situation so that the light forms a rainbow. What shape did you choose? o A trapezoid formed a rainbow. Exploration 2: case R f x o x i 1/x 0 + 1/x i 1/f M image real? image upright? concave mirror, real image: |hi| > |ho| 10 5 8 13.3 .2 .2 -1.655 yes No concave mirror, real image: |hi| < |ho| 10 5 10.48 9.56 .2 .2 -.91 Yes No concave mirror, virtual image 12 5 4.5 -10 1/6 1/6 3 No Yes convex mirror -8 -4 8 -2.67 -.249 -.26 .335 No Yes  Paste the table into your log.  Discuss your results. o Based on my results the height of the object is greater than the height of the image, the mirrors labeled as a convex mirror. The images that were viewed were both inverted and the convex mirror was produced from a negative R.  Can you think of situations where spherical mirrors are used to produce the images explored in case 1 - 4. o An example of this is a magnifying glass or mirrors on a car or binoculars.

Experiment: Use your spreadsheet to calculate g lass for each of your 4 measurements. Paste your spreadsheet table into your log.  Do your measurements agree with each other within reasonable uncertainty, given how you performed your measurements. o Some of the measurements obtained are agreeable and within reasonable uncertainty. This is because the angles of air increased when the bean is passed through the glass. This then causes the Glass to decrease.  Do you suspect some of the measurements to be more accurate than others? If yes, why? o Some of the measurements are more accurate than others because of the distance at ¼ and 2/4 were estimated values compared to ½ and 1. The position of the postholder also made a difference with the values.  From your measurements, what do you conclude is the index of refraction n + An of the glass block? o The index of the glass block is around .4 based off using the formula. Reflection: In conclusion, after completing the refraction lab I was able to conclude the behavior of light at the boundary between two transparent media with different indices of refraction. In exploration 1, I was able to use the stimulation to conduct how a laser would move through different materials. Using Snells law, I was able to conduct a graph that was linear. This allowed me to understand the index of the refraction of water. In addition, in the second part of the experiment I could control how the laser refracted through different material. As we saw, when the triangle was used it went right through and when a trapezoid was used with specific lighting and wavelength it turned rainbow. In the second exploration. I was able to investigate 4 different situations and create a spreadsheet top produce image. Specifically, the interactive stimulation allowed me to see the ray diagram as well as the positionings of the images. I was able to conclude the heights and position of the images through the concave mirrors and convex mirror. Specifically, I could compare my results to a magnifying glass it works the same way. In the last experiment, I had a difficult time getting me excel to work I was able to calculate