Name_________________________
Snell’s Law—PhET Simulation

1. Go to the PhET website. https://phet.colorado.edu/ 2. Choose “play with simulations.” Next, chose >Physics, >Light and Radiation, and choose >Bending Light. 3. Learn how to turn on the laser. Play with moving the angle to change the angle of incidence. Figure out how to use the protractor to measure angle of incidence and angle of refraction. Use the light intensity meter to figure out how to measure the percent of the ray that is refracted and reflected. Play with how a ray looks different than a wave. 4. Use the “Reset All” button. Align the protractor. Set up an angle of incidence of 60°. • What is the angle of refraction? ________ • What is the angle of reflection?_______ • What is the intensity of the refracted ray?________ • What is the intensity of the reflected ray?_______ 5. Change the upper medium to glass. Change the bottom medium to air. • Use the protractor to measure the critical angle._____ (Remember to measure from the normal, not the boundary.) _______ • What is the intensity of the reflected ray? ________ • Now use the shown indexes of refraction with Snell’s Law to check your measured critical angle. Show all work below.

5. Hit the “Reset All” button. 6. Make the top medium glass and the bottom medium water. • Using the protractor, measure the critical angle for light going from glass into water._____ • Use the indexes of refraction and Snell’s Law to support this measurement.

7. Click the >Prism Break tab at the top of the page. Choose a shape. Familiarize yourself with the different options. Notice that you can rotate each prism by clicking and dragging the metallic handle on the corner of the prism. You can also rotate the light source itself. You can even make the protractor larger! • Use