1. Reflection and Refraction Chapter 17

2. Law of Reflection θiθi θrθr θ i angle of incidence θ i angle of reflection

3. Law of Reflection θiθi θrθr θ i = θ r

4. Types of Reflection Regular Diffuse

5. Refraction of Light θrθr θiθi θiθi θrθr Air(n i ) Glass(n r ) n i < n r

6. Index of Refraction n (Optical Density) Air: n i Glass: n r n i < n r

7. Refraction of Light θrθr θiθi nini nrnr n i < n r nini nrnr θrθr θiθi n i > n r

8. Snell’s Law θrθr θiθi nini nrnr n i sin θ i = n r sin θ r

9. A ray of light has an angle of incidence of 25.0  upon the surface of a piece of quartz. What is the angle of refraction? θiθi θrθr Air: n i = 1.00 Quartz: n r = 1.54

10. Given: n i = 1.00 n r = 1.54 θ i = 25° Find: θ r Equation: n i sin θ i = n r sin θ r sin -1 (sin θ i /n r )= θ r sin -1 (sin 25° /1.54)= θ r θ r = 17 °

11. Speed of Light and The Index of Refraction n n = c v n: index of refraction c: speed of light in a vacuum v: speed of light in material

12. What is the speed of light in diamond? Given: n D = 2.42 c = 3.0 X 10 8 m/s Equation: v D = c/n D v D = 3.0 X 10 8 m/s / 2.42 v D = 1.2 X 10 8 m/s Find: v D

13. Homework: 17-1 Practice Problems: 1-8 Page: 400, 402 Review: 17-1 Page: 402 Due: 4/8/03

14. Homework: 17-2 Probs: 31,33,34,39,41,43 Page: 411-412 Due: 4/11/03 Test:4/15/03

15. Total Internal Reflection

16. n1n1 n2n2 n 2 > n 1

17. Total Internal Reflection n1n1 n2n2 n 2 > n 1 Critical Angle 90º θcθc

18. Total Internal Reflection n i sin θ i = n r sin θ r n i sin θ c = n r sin 90º n i sin θ c = n r (1) sin θ c = nini nrnr

19. Total Internal Reflection θ c = sin -1 nini nrnr

20. Example: What is the critical angle between water and air? Given: n w = 1.33 n a = 1.00 Given: θ c = sin -1 nini nrnr θ c = sin -1 1.33 1.00 θ c = 49°

21. Mirage

22. Diamonds (n = 2.42)

23. Fiber Optics

24. Dispersion cause by Refraction Prism

25. The amount that light is diffracted depends on its wavelength. Shorter wavelengths are bent more than longer wavelengths. Violet is bent more than Red!!!

26. Rainbow

27. Spectroscopy

29. Homework: 17-3 Problems: 50,51 Page: 412 Study Guide Due: 4/14/03 Test: 4/15/03