1. AP Physics 2 Unit 7 Refraction and Physical Optics

2. Refraction and Lenses

3. Refraction – the bending of light as it passes between two media with different optical densities

4. The index of refraction

5. Ex. The index of refraction for a diamond is 2.42. What is the wavelength of green light in a diamond if the frequency of light in air is 5.45 x 10 14 Hz?

6. Snell’s Law – “Proof Ahoy”

8. Ex. Light is incident in air (n air = 1.00) upon an equilateral crown glass prism (n g = 1.52) at an angle of 45.0⁰ to one face. Calculate the angle at which the light emerges from the opposite face.

9. Total Internal Reflection

11. Ex. A ray of light in a diamond (n = 2.42) strikes an interface at 28⁰. Will the beam of light enter the air or will it be reflected internally? Will the beam of light be reflected internally if the diamond is surrounded by water (n w = 1.33)?

12. Applications of total internal reflection

13. Dispersion of Light

14. Lenses

15. Two types of lenses

16. Images formed by converging lenses

17. Image formed by a diverging lens

18. A familiar friend

19. Sign conventions for lenses: f is positive for converging lenses and negative for diverging lenses s o is positive when light is reflected from the object (a real object) s i is positive when it is behind the lens (real image) and negative when it is in front of the lens (virtual image)

20. Physical Optics

21. First, what is diffraction of light? The trumpet and the spotlight outside of the door.

22. Huygen’s Principle

23. Linear Superposition

24. Young’s Double Slit Experiment and Wave Properties of light

25. Bright and dark fringes, also known as maxima and minima also known as bright and dark bands

26. Position of the maxima and minima

27. “Order in the fringe!”

28. Intensity of the maxima and minima

29. Two equations for double-slit interference

31. Ex. The distance between two slits is 1.20 x 10 –4 m. An interference pattern is projected onto a screen 2.75 m away. Find the distance on the screen between the central maximum and and the third order maximum.

32. Single slit interference

33. Diffraction grating

34. The electromagnetic Spectrum

35. All wave of e-m spectrum travel at the speed of light c (2.99 x 10 8 m/s, like really, really fast). Note the relationship between wavelength, frequency and energy.

36. E-m spectrum Radio (AM, FM, TV) > 30 cm Microwaves (radar, atomic-molecular research, microwave ovens) between 30 cm and 1 mm Infrared between 1 mm and 700 nm Visible light between 400 nm and 700 nm Ultraviolet between 400 nm and 60 nm X-rays between 60 nm and 10 -4 nm Gamma rays between 0.1 nm and 10 -5 nm

37. Polarization of Light

38. Let’s look at unpolarized light first

39. The fence and the rope