PHYC 110 Physical Science Name _______________ Date ________________ Exercise 12: Light and Optics Speed of light in a vacuum c =3.0x108 m/s 1. The index of refraction of glass is 1.5. How fast does light travel through glass? Given Formula n = 1.5 n = c/v 8 c = 3.0x10 n = 1.5 = c/v = 3.0x108/v v = c/n = 2.0x108 m/s 2. The speed of light in a particular type of glass is measured to be 1.60 x 108 m/s. What is the index of refraction of this glass? Given Formula 8 v = 1.6x10 n = c/v c = 3x108 n = c/v = 3.0x108/1.60x108 = 1.85 3. Sketch a ray diagram for a spherical convex lens with an object at a distance (20 cm) twice the focal length (10 cm) from the lens (see figure). Describe the image characteristics: a. real or virtual b. upright or inverted c. increased in size or reduced in size d. Estimated distance from lens. a. real b. inverted c. about the same d. 20 cm. normal 4. A light ray strikes a flat mirror with a 30-degree angle of incidence. Draw a ray diagram to show how the light ray interacts with the mirror. Label the normal line, the incident ray, and the reflected ray. 5. Light, being a transverse wave, can be polarized. Can sound waves be polarized? How would it sound? Sound is a longitudinal wave and cannot be polarized. incident ray reflected ray