1. WAVES: SOUND & LIGHT Waves carry energy from one place to another

6. Electromagnetic Spectrum © 2000 Microsoft Clip Gallery

19. Refraction (Cont.)

20. Geometry Refresher A B   C parallel lines given A:      

21. Electrical Component Magnetic Component Electromagnetic Wave In optics ignore magnetic component

22. Wavelength and Frequency Wavelength: Distance between adjacent troughs or crests   nm (10 -9 m) Frequency: Number of times cycle repeats per second f Hz ( sec -1 ) Speed = Frequency X Wavelength v = f 

23. Speed of light in vacuum , C = 3 x 10 8 m/sec Speed is slower in matter Air New Medium Speed = C Speed = V

24. medium 1 medium 2 n 1 n 2 REFRACTION Snell’s Law: n 1 sin    n 2 sin     angle of incidence   angle of refraction

25. Snell’s Law n 1 sin   = n 2 sin   n 1 = 1.00 30 o n 2 = 1.50 ? o 19.47 o

26. Willebrord van Roijen Snell 1580 - 1626 Professor of Mathematics University of Leiden, Netherlands

27. lower n higher n Ray bends toward normal Which way do the rays bend in refraction?

28. higher n lower n Ray bends away from normal

30. Reflection and Refraction Light is reflected as well as refracted at surfaces. refracted ray reflected ray n n’  i  r n’ > n incident ray  i =  r

45. Sign Conventions for Lenses Diverging Lens Converging Lens Focal Length (f) (1/2 Radius of Curvature, C) Image is inverted Image is upright Image height ( h ’) Image is in front of surface (virtual) Image is in back of surface (real) Image location ( Di ) Object is in back of surface Object is in front of surface Object location ( Do ) Negative When Positive When Quantity