1. AP Physics 2 Unit 6 Wave Motion and Geometric Optics

2. Two features common to all mechanical waves A wave is a traveling disturbance A wave carries energy from place to place without transferring matter

3. Two types of waves Transverse – the disturbance is perpendicular to the direction of the motion Longitudinal – the disturbance is parallel to the direction of the motion

4. Wave terminology Equilibrium position Crest and trough Wavelength Amplitude Period Frequency

5. Importante – the frequency of the wave is determined by the source. The speed of the wave is determined by the medium.

6. Mathematical Description of a Transverse wave

7. Superposition of waves

8. Reflections of a wave at a fixed and free end.

9. Standing waves – demo

10. The electromagnetic Spectrum – no medium required

11. All waves of electromagnetic spectrum spectrum travel at the speed of light, c = 2.99 x 10 8 m/s. Note the relationship between wavelength, frequency and energy.

12. The electromagnetic spectrum Radio (AM, FM, TV) > 30 cm Microwaves (radar, atomic-molecular research, m-wave 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 EE -4 nm Gamma rays between 0.1 nm and 10 EE -5 nm

13. Electromagnetic waves are transverse waves composed of alternating electric and magnetic fields

14. Polarization of Light

15. Let’s look at unpolarized light first

16. The fence and the rope

17. Geometric Optics

18. Wave Fronts and Rays

19. Reflection of Light

20. Law of Reflection

21. Specular (regular) and diffuse reflection

22. Is all of the light incident upon the mirror reflected?

23. Plane Mirrors

24. Five Properties of the image of a Plane Mirror Upright Same size Located as far behind the mirror as the object is in front of the mirror Left to right reversed Virtual image

25. Ray Diagram for a Plane Mirror

26. Spherical Mirrors (concave – converging and convex – diverging)

27. The focal length and radius of curvature

28. Ray diagrams for curved mirrors. Only two rays are needed to locate an image Any ray drawn parallel to the principal axis is reflected through the focal point Any ray drawn through the focal point is reflected parallel to the principal axis Any ray incident upon the mirror is reflected at the same angle when measured from the normal Any ray drawn through the center of curvature is reflected upon itself

29. Six ray diagrams for converging (concave) mirrors

30. Only one ray diagram for convex (diverging mirrors)

31. The mirror equation and magnification (and an impressive proof thrown in for free)

33. Summary of sign conventions for curved mirrors f is positive for a concave mirror and negative for a convex mirror s o is positive for an image located in front of the mirror (our only concern at this point) s i is positive for a real image (in front of the mirror) and negative for a virtual image (behind the mirror)

34. Ex. A 2.00 cm object is placed 7.10 cm from a concave mirror whose radius of curvature is 10.20 cm. Find the location and size of the image.

35. Ex. An object with a height of 1.20 cm is placed 6.00 cm in front of a concave mirror with a focal length of 10.0 cm. Find the location and height of the image.

36. Ex. An object is placed 66 cm in front of a convex mirror that has a focal length of 46 cm. Find the image distance and magnification.