1. Mav Mark What are forms of the electromagnetic spectrum?

2. Mav Mark What are the primary colors of LIGHT? All colors of light in equal amounts make what color? What are the primary colors of PIGMENTS? All colors of pigments in equal amounts make what color?

3. Mav Mark Write the Law of Reflection Draw an example Label the angle of incidence and the angle of reflection

4. Mav Mark Compare Concave and Convex Mirrors

5. Mav Mark If you were stranded on an island and needed to start a fire, which type of lens would you need to help you? Explain why.

6. Light

7. Electromagnetic Spectrum

8. 1. Light When light strikes an object, it may be – Reflected – Transmitted – Absorbed

9. 1. Light Reflected Light Transmitted Light Absorbed Light

10. 2. Transparent Material Transmits most of the light that strikes The light passes through without being scattered You can clearly see through Ex: Clear glass, water, air

11. 3. Translucent Material Scatters light You can see through, but the object is blurred Ex: waxed paper, frosted glass

13. 4. Opaque Material Reflects or absorbs the light that strikes it You can NOT see through Ex: wood, metal, fabric

14. 5. Color of Opaque Objects The color of an opaque object depends on the light it reflects

15. 6. Color of Transparent and Translucent Objects The color of a transparent or translucent object is the color of the light it transmits

16. 7. Color Filters Allows only one specific color to pass through causing objects to look different than when they are seen through white light Ex: sunglasses

17. Try This:

18. 8. Primary Colors Three basic colors that can combine to make any other color are primary colors When combined equally, they make white light The primary colors of light are: – Red – Green – Blue

19. Mav Mark

20. 9. Secondary Colors Primary colors combine to form secondary colors Two colors that combine to form white are called complementary colors The secondary colors of light are: – Yellow – Cyan – Magenta

21. 10. Pigments Pigments are used to color other substances When pigments are added together, fewer colors are reflected and more are absorbed The Primary colors of pigments – Magenta – Cyan – Yellow

22. 10. Pigments The Secondary colors of pigments are: – Red – Green – Blue

23. Reflection and Mirrors

24. 1. Rays Rays are straight lines that represent how light is reflected Two types of reflections: – Regular (smooth surface) – Diffuse (bumpy surface)

25. 2. Plane Mirrors A plane mirror is a flat sheet of glass with a smooth, silver coating on one side – Smooth coating gives a regular reflection

26. 3. Images An image is a copy of an object formed by reflected or refracted rays of light Plane mirrors show a virtual image (does not really exist)

27. 3. Images Virtual images in a plane mirror are reversed

28. 4. The Law of Reflection When a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection

29. 5. Optical Axis and Focal Point An optical axis is an imaginary line in the middle of the mirror A focal point is the place where all of the rays meet Optical Axis Focal point

30. 6. Concave Mirrors The surface of a concave mirror curves in (like the inside of a bowl) The focal point is in front of the mirror Uses: – Dental mirrors – Car lights – Telescopes – Make-up mirrors

31. 6. Concave Mirrors Concave mirrors help you to see a larger image Concave mirrors can also form a real image – A real image is the image formed where the rays actually meet – Upside down

33. 7. Convex Mirrors The surface of a convex mirror curves out The focal point is behind the mirror Uses: – Rear-view mirror out-side the car – Security mirror – Sunglasses – Telescopes

34. 7. Convex Mirrors Convex mirrors allow you to see a larger area – The image is much smaller

35. Refraction and Lenses

36. 1. Refraction Refraction is the bending of light The speed of light is different depending on what medium it travels through – Air – Water – Quartz – Glass – Oil

37. 2. Index of refraction The index of refraction is a measure of how much light bends in a particular substance air oil water

38. 3. Prisms and Rainbows Each color of light has a different wavelength and is refracted differently – Red (long wavelength; bends the least) – Orange – Yellow – Green – Blue – Indigo – Violet (shortest wavelength; bends the most)

39. 4. Mirages A mirage is an image of a distant object that is caused by refraction of light – Light travels faster in hot air

40. 5. Lenses A lens is a curved piece of glass or other transparent material Lenses can be – Convex – Concave

41. Real Image vs Virtual Image A Real image is made from real light rays that can converge (bring light together) at a real focal point so the image is REAL – It can be projected onto a screen – It is always inverted (upside down) A Virtual image seems to be there, but it isn’t – It is right-side up – It is reversed (WAVY - YVAW)

42. 6. Convex Lenses Convex lenses are thicker in the middle than the edges They can form a real or virtual image depending on the object’s distance from the lens Uses – Cameras – Magnifying lenses

43. 6. Convex Lenses Convex lenses bend light toward the center of the lens – Converging – Bend toward

44. 7. Concave Lenses Concave lenses are thinner in the center than the edges They can only form a virtual image Uses: – Correct nearsighted vision

45. 7. Concave Lenses Concave lenses bend light away from the center of the lens – Diverging – Bend away from

46. Are You Nearsighted? If you can’t see objects far away, then you are nearsighted Your vision is corrected by diverging lenses

47. Or Are You Farsighted? If you can not focus on objects nearby, then you are farsighted Your vision is corrected by converging lenses

48. Using Light

49. 1. Optical Instruments Help us to see objects more clearly – Telescopes – Microscopes – Cameras

50. 2. Telescopes Use lenses and mirrors to focus distant objects and make them appear larger – Refracting telescope (uses two convex lenses) – Reflecting telescope (uses a concave mirror)

51. Refracting Telescope Uses two convex lenses

52. Reflecting Telescope Uses a large concave mirror

53. 3. Microscopes Uses a combination of lenses to produce and magnify an image – Eyepiece (10X or 15X magnification) – Objectives (4X, 10X, 40X, and 100X)

54. Microscopes Use a combination of lenses

55. 4. Cameras Uses lenses to focus light and form a real image on film

56. 5. Lasers L ight A mplification by S timulated Emission of Radiation Lasers are a beam of light with the same: – Wavelength – Color