1. DO NOW What is the color of a light wave with a frequency of 5.65 x 10 14 Hz?

2. Refraction of Light

3. Refraction Refraction is the bending of a wave when it enters a medium where it's speed is different.

4. Snell’s Law The slower the speed, the smaller the angle Sinθ 1 Sinθ 2 v1v1 v2v2 =

5. Snell’s Law

6. Monochromatic light passes between two media. If the angle in medium 1 is 45° and the angle in medium 2 is 30°, calculate the ratio of the light speeds between media 1 and 2. V 1 = 1.4v 2

7. Absolute Index of Refraction Always greater than or equal to zero The larger n, the slower the speed of light in a medium

8. Absolute Index of Refraction The speed of light in a medium is 2.4 x 10 8 m/s. What is the absolute index of refraction of the medium? 1.25

9. Snell’s Law n 1 sinθ 1 = n 2 sinθ 2 n2n2 n1n1 v1v1 v2v2 =

10. Snell’s Law A monochromatic light ray is incident on a surface boundary between air and corn oil at an angle of 60° to the normal. Calculate the refracted angle of the ray in the corn oil. n 1 sinθ 1 = n 2 sinθ 2 θ 2 = 36°

11. Critical Angle

12. Calculate the critical angle between diamond and Lucite. θ c = sin -1 (n 2 /n 1 ) θ c = 38°

13. Total Internal Reflection If the critical angle is exceeded, the light can no longer escape but will be reflected back into the medium.

14. Total Internal Reflection

15. the light is in the more dense medium and approaching the less dense medium. the angle of incidence is greater than the critical angle.

16. Dispersion Speed of light in the prism depends on the color of the light (frequency)

17. Practice! Page 493: Practice A- 1 & 3 Page 493: Section Review – 1 – 4 Page 508: Practice C- 1 & 2 Page 511: Section Review- 1 & 3

18. Draw a diagram of a ray of light traveling from an unknown medium into glycerol. If the angle of incidence is 40 degrees and the angle of refraction is 46.5 degrees, what is the index of refraction of the unknown medium? Is it more or less dense than glycerol?

19. EXIT QUIZ A ray of light travels from water into air with an incident angle of 23 degrees. What is the angle of refraction?