ElliottBrooks_Lab7

Name: Elliott Brooks Samantha Reasonover E-mail address: ebrook26@vols.utk.edu Samantha Reasonover Laboratory 7 Report Goal: The goal of this laboratory was to better understand refraction and reflection. Through understanding these it was easy to see how their relationship is with one another and also the relationship they share in calculating the relating variables. Reflection: I found this lab to be both interesting and difficult. I greatly enjoyed learning through the simulation more about the way light may be refracted or resolved however, the difficulty of working the simulations took time out of me actually conceptualizing the ideas. I enjoyed how throughout the entire lab, each experiment sorta built off of each other - as I feel this is not always the case. All in all, not my favorite lab due to the time it took me just to figure out the simulations. Exploration 1 ● Plot R versus theta. Paste your graph into your log. Compare to the graph above. ● ● Discuss your result. ○ Is the laser light p-polarized, s-polarized, or unpolarized. What do your results suggest? ○ My results suggest similarities between the graph I was able to produce and the graph given on labman. The graph on labman, however, is exponentially positive whereas mine shows a more neutral slope. Given that I have followed all instructions and collected sufficient data, I believe this to be an error on excel’s end. Additionally, after using the sin formula given on labman, my laser light appears to be s-polarized. ● Calculate sinθ i and sinθ t . Remember that Excel functions require the angles to be in radians. The first row if the spreadsheet already contains the formulas. ● Plot sinθ i versus sinθ t .

○ What does the plot look like? ○ The plot is linear, steadily increasing ○ Use the trendline to find the slope. Paste the graph with trendline into your log. ○ What value do you obtain for the slope? ○ The slope is 0.7503x ○ Given Snell's law, what value do you expect for the slope? Discuss! ○ Snell’s law is n i sinθ i = n t sinθ t and approves our slope by suggesting that the slope should be 1 or a value close to it, given that Snell expects n i sinθ i to equal n t sinθ t (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 A and n B ? ● I believe that the same procedure I just followed may be helpful in determining the index of refraction for the two mystery materials. First I set up my phet simulation to show air on top and then Mystery A, followed by Mystery B on the bottom. I followed all instructions as stated for the first portion of our lab, computing the degrees and refractions 8 times, 0 degrees - 80 degrees, converted my degrees to radians, utilized the same excel log, using the same sin formulas to obtain a graph and get a slope from it. ● My nA = 2.5710 ● My nB = 1.3203 (c) Design and describe a setup that has the refracted ray bend away from the normal? ● I believe to produce a refraction bend the opposing way you would need to make sure a material with a low index of refraction on the bottom material and a high index of refraction on the top. ● Paste a screen shot of your setup into your log.

What shape did you choose? ● I chose the sphere! ● Exploration 2: Investigate 4 different situations and fill out the table on sheet 3 of your spreadsheet. You choose the radius of curvature R and the object position x o . ● Use a concave mirror to produce a real image which is bigger that the object. ● Use a concave mirror to produce a real image which is smaller that the object. ● Use a concave mirror to produce a virtual. ● Use a convex mirror to produce an image. 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| 8.93 2m 4.466 8.4 - 9.72 0 0.01 62 0.224 1.157 no yes concave mirror, real image: |hi| < |ho| 8.107 m 4.054 8.4 - 7.52 0 - 0.01 39 0.247 0.895 no yes concave mirror, virtual image 57.2 28.6 7.70 10 0.22 99 0.0350 - 1.299 yes inverte d

convex mirror -14.2 -7.1 7.70 3.49 0.41 64 -0.141 -0.45 3 yes inverte d ● Paste the table into your log. ● Discuss your results. ● Our results were interesting to see through the relationships each variable holds with another. One thing my data infers from my own experiment that did not line up with what I read through the laboratory procedure was that 1/x o + 1/x i = 1/f. This did not ring true for me, however, as shown on my table. ● Can you think of situations where spherical mirrors are used to produce the images explored in case 1 - 4. ● Real life examples of a concave spherical mirrors includes a bathroom mirror! A real life example of a convex mirror may include our car mirrors! Experiment Use your spreadsheet to calculate n glass for each of your 4 measurements. Paste your spreadsheet table into your log. w d θair deg θair rad cos2θ air sin2θa ir d/(w sinθair) (1 - d/(w sinθair))2 n2 n 2. 8 0.2 5 9.6 0.16 8 0.999 983 0.005 86 30.45 867.3 0.007 01 0.083 7 2. 8 0.5 21 0.36 7 0.999 918 0.012 8 27.88 722.5 0.014 18 0.119 08 2. 8 0.7 5 33 0.57 6 0.997 9 0.020 1 26.64 657.4 0.021 6 0.146 97 2. 8 1 45 0.78 5 0.999 62 0.027 4 26.068 628.4 0.028 99 0.170 26