Reflection and refraction lab report discussion

Reflection and Refraction Virtual Lab Phys204L/206 Instructions: Read through the introduction material thoroughly. Print out your data tables and analysis questions. Complete the procedure and record the results in the Data Tables. Answer all analysis questions. Turn in your printed out data tables and analysis questions at the beginning of our next lab. Introduction In this virtual lab you will explore how light behaves as it interacts with various materials. Light can be reflected (bounced off a surface) or refracted (bent at an angle as it goes from one medium to another). The medium is the material the light travels through. Each medium has an index of refraction, indicated by the letter “n.” The index of refraction has no units and describes how the speed of light changes in different media. For reference, the index of refraction of a vacuum (and most gases, like air) is 1. How to run the simulation: 1. Go to the link: https://phet.colorado.edu/en/simulation/bending-light 2. Click the “Play” button on the simulator. 3. Select “Intro” from the menu options. Description of the Simulation In the simulation there are many options. Below is an brief description of these options. a. Laser: can be moved to different angles by clicking and dragging, red button turns laser on and off b. Normal line: The “normal” is an imaginary line meets the surface of a material at a right angle. It is the line you will be measuring from using the protractor (f.). c. Incident ray: Emitted from the laser d. Reflected ray: Reflects off material e. Refracted ray: Travels through material f. Protractor g. Material 1 options (can select from air, water, glass or manually change the value of n) h. Material 2 options (can select from air, water, glass or manually change the value of n) Taking Measurements with the Simulation To measure, click and drag the protractor so it is aligned as pictured to the left: Make sure the “0” measurement is lined up with the normal. Make sure the “90°” measurement is lined up with the material edge. The angles are defined as follows: θ1: Angle of the incident ray with the normal θ2: Angle of the refracted ray with the normal θr: Angle of the reflected ray with the normal Procedures Part 1: Reflection 1. 2. 3. 4. 5. Align the protractor as shown in the “Taking Measurements” section. Set Material 1 as “Air” and Material 2 as “Glass.” Place the laser so the incident ray has an angle θ1 = 80° with the normal. Measure θr, the angle of the reflected ray. Record this angle in Data Table 1. Repeat steps 3-4 for θ1 = 60°, 40°, 20°, 0°. Part 2: Refraction from air to glass 1. 2. 3. 4. 5. 6. 7. 8. Align the protractor as shown in the “Taking Measurements” section. Set Material 1 as “Air” and Material 2 as “Glass.” Record the values of n1 and n2 in your data table. Place the laser so the incident ray has an angle θ1 = 10° with the normal. Measure θ2, the angle of the refracted ray. Record this angle in Data Table 2. Repeat steps 3-4 for θ1 = 15°, 20°, 25°, 30°, 35°. For each measurement calculate the values of sin θ1 and sin θ2 . Record the result in your data table. For each measurement calculate the value of sin θ1 / sin θ2 . Record the result in your data table. Experiment with incident angle of the laser and observe what happens to the refracted ray at large and small angles. Make note if there is a critical angle where the refracted ray disappears. Part 3: Refraction from water to air 1. 2. 3. 4. 5. 6. 7. 8. Align the protractor as shown in the “Taking Measurements” section.