Physics 109 1st Edition Lecture 2 Outline of Last Lecture I. Light and ColorII. Reflectiona. Specular Reflection b. Diffuse ReflectionIII. Reflection from a mirror Outline of Current Lecture I. Refraction of Light a. Snell’s lawII. Total Internal ReflectionIII. Refraction ExamplesCurrent LectureIV. Refraction of Light a. When light penetrates into a denser medium the rays are kinked toward the normal-(air to water) This kinking is called refraction. b. When light penetrates into a less dense medium the rays are kinked away from the normal (water to air)c. The behavior in a medium depends on the index of refraction of the medium, n. i. The denser the medium, the higher the index of refractiond. Snell’s law shows how the angle in air and the water are relatedi. Sin angle air/sin angle water=n air/ n water These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.V. Total Internal Reflection a. No light is refracted, all light is reflected from the interfaceb. Total internal reflection (TIR) is the phenomenon that involves the reflection of allthe incident light off the boundary. TIR only takes place when both of the following two conditions are met:i. the light is in the more dense medium and approaching the less dense mediumii. the angle of incidence is greater than the so-called critical angle.c. We can calculate the critical angle by using Snell’s Law. The critical angle in air is 90 degrees. Since we know that the index of refraction for air = 1 and the sin90=1, we can find the critical angle by using Critical angle (water)= inverse sin (1/n water)VI. Refraction Examplesa. Does the fish appear above or below its real position? The fish appears to be above its actual position because of refractionb. If angle air=30 degrees, what is angle water? (n water=1.33)Angle w= inverse sin (1/1.33)(sin 30) = (.5/1.33)= 22 degreesNote: sin 30=