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Snell’s Law Lab Activity In this activity you will find out if the angle of incidence of a ray that strikes an acrylic dish compares with: The angle of reflection The angle of refraction of the acrylic dish Pre-Lab Questions: 1. What is Snell’s Law and what is it used for? 2. Write out what each of the variables represents. 3. Re-arrange Snell’s Law to solve for n1 and n2. Materials: __________ half circle Protractor Graph paper Ruler Ray box with single slit plate Procedure: 1. Draw a horizontal line on graph paper. Label the line as: Normal. 2. Draw a perfectly perpendicular line to your normal. Label the intersection as O (origin). 3. Use a protractor and draw lines with angles of incidence that are 10, 20, 30, 40, 50 from the normal. 4. Line up your half circle on the perpendicular line so it is split in half by the normal. 5. Direct a single ray from a ray box along your angled lines of incidence. Mark the line of reflection and refraction. 6. Draw all lines in full and measure all angles of reflection and refraction. normal i1 r1 R1 Observations: Air Angle of Incidence (i) 0 10 20 30 40 50 Angle of Reflection (r) Unknown Angle of Refraction (R) 7. Using a scientific calculator, find the sine value of the Angles of Incidence and Angles of Refraction. Air Angle of Incidence (i) 0 10 20 30 40 50 sini Unknown Angle of Refraction (R) sinR 8. Using the Snell`s Law calculation, find the index of refraction for your unknown substance at each angle (6 calculations total). After this is complete, take an average of your results to find a final index of refraction. PLEASE SHOW YOUR WORK!!! 9. Research the likely identity of the unknown substance, by comparing which substance(s) BEST match your value for the index of refraction. 10. Compare your value, and identity to 2 other groups. Conclusion: Answer using complete sentences. What was the identity of the unknown object? How did your results compare to the other 2 groups? How could you explain any differences you may have had in your results or conclusions? Explain the significance of the measuring the values for r. Identify and explain and sources of error in this experiment that could alter your results. WHAT TO SUBMIT: 1. 2. 3. 4. 5. Pre-Lab Questions Drawings Observation tables Calculations (Show complete work for 1 of each type of calculation) Conclusion paragraph