1. OK everyone get ready to learn a new vocabulary term.

2. Law of Reflection
Today we are going to be defining the Law of Reflection.

3. Concave mirror
We will be learning about concave mirrors,

4. Convex mirrors
convex mirrors,

5. Focal point
the focal point,

6. Focal length
and focal length.

7. Before we define these terms, let’s review some other words that you already learned, and make sure you are firm in your understanding.

8. Electromagnetic Waves
Electromagnetic waves have both a magnetic field and electric field. The electromagnetic spectrum shows you all possible electromagnetic waves.

9. Visible Light
One type of electromagnetic wave is visible light. It is the only kind of electromagnetic wave we are able to see.

10. Radiant Energy
Electromagnetic waves carry radiant energy.

11. Medium
A medium is any material that waves can travel through.

12. reflection
Reflection occurs when a wave bounces off of a surface.

13. Now let’s pause for a moment to review the information we have covered already.

14. What type of light can humans see?
Visible Light

15. What are electromagnetic waves?
Waves that have both electric fields and magnetic fields.

16. Law of reflection
Now, let’s define what the law of reflection means

17. Law of reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.
The law of reflection states that when a wave is reflected on a surface, the angle of reflection equals the angle of incidence. We are going to break this down.

18. Law of Reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.
First we have to remember that waves are reflected on the surface.

19. Surface
Here we are looking at the surface.

20. Law of Reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.
Now we have to know what the angle of incidence is. The angle of incidence is the light wave that strikes the surface.

21. Angle of Incidence
Here we are looking at the surface.

22. Law of Reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.
The angle of reception is why we can see the mountains and sky in the water.

23. Angle of Reflection
Here we are looking at the surface.

24. Law of Reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.

25. Normal
Here we are looking at the surface.

26. Now let’s pause for a moment to review the information we have covered so far.

27. What is the angle of incidence?
The angle in which the light hits the surface.

28. The law of reflection states that the angle of incidence is ______ the angle of reflection?
greater than
less than
equal to
The law of reflection states that the angle of incidence is ______ the angle of reflection?
greater than
less than
equal to

29. The law of reflection states that the angle of incidence is ______ the angle of reflection?
greater than
less than
equal to
The law of reflection states that the angle of incidence is equal to the angle of reflection.

30. What line is used to reference the angle of incidence and angle of reflection?
Normal

31. Surface
The type of surface affects the reflection.

32. Regular reflection
Now, let’s define what regular reflection means

33. Regular reflection: reflection of light from a smooth, shiny surface.
A regular reflection is the reflection of light from a smooth, shiny surface.

34. Diffuse reflection
Now, let’s define what diffuse reflection means

35. Diffuse reflection: reflection of light from a rough surface
A diffuse reflection is the reflection of light from a rough surface.

36. Normal

37. The normal will always be perpendicular, or 90 degrees, to the surface.

38. Now let’s pause for a moment to review the information we have covered so far.

39. Which reflection occurs on a rough surface?
diffuse
regular
Which reflection occurs on a rough surface?
diffuse
regular

40. Which reflection occurs on a rough surface?
diffuse
regular
Diffuse reflection occurs on a rough surface.

41. True or False: The normal is always parallel to the surface.

42. True or False: The normal is always parallel to the surface.

43. Concave mirror
Now, let’s define what concave mirror means

44. Concave mirror: a mirror that curves inward
A concave mirror is a mirror that curves inward.

45. Concave
Let’s look at a clue that will help us remember the definition of concave.

46. Concave
Here you can think of cave like caving in since concave mirrors bend inwards.

47. Focal point
Now, let’s define what focal point means.

48. Focal point: point where light rays converge to make an image
The focal point is where light rays converge to create an image.

49. Real and Inverted Image
Object
Image of object
An object outside the focal point creates a real inverted image.

50. Real and Inverted Image
Object
Image of object
Notice the object is on the same side and flipped upside down.

51. Virtual and Upright Image
Image of object
Object
An object outside the focal point creates a real inverted image.

52. Virtual and Upright Image
Image of object
Object
Notice the image is not on the same side.

53. Focal length
Now, let’s define what focal length means.

54. Focal length: distance along the optical axis between the focal point and the mirror
The focal length is the distance along the optical axis from the mirror.

55. Explicit cue to review examples of concave:
Now, let’s talk about some common examples of surfaces that are concave.

56. Spoon
The curved inside of a spoon is concave.

57. Metal Bowl
The inside of a bowl is a concave surface.

58. Now let’s pause for a moment to review the information we have covered so far.

59. Light rays _______ to create a focal point.
Converge
Diverge

60. Light rays _______ to create a focal point.
Converge
Diverge

61. What is focal length?
The distance from the focal point to the surface.

62. True or False: Concave mirrors create images that are either virtual and upright or real and inverted

63. True or False: Concave mirrors create images that are either virtual and upright or real and inverted

64. Convex Mirror
Now, let’s define what convex mirror means.

65. Convex Mirror: a mirror that curves outward
A convex mirror is a mirror whose surface curves outwards.

66. Explicit cue to review examples of convex

67. Convex Mirror
This mirror has a convex surface. It helps drivers see other cars more easily.

68. Diverge
Convex mirrors cause light rays to diverge.

69. Now let’s review everything we’ve covered today.

70. Light waves ________ on the focal point.
Converge
Diverge

71. Light waves ________ on the focal point.
Converge
Diverge

72. Concave mirrors curve _______
inward

73. Is the top of the spoon a concave mirror?

74. True or False: Convex mirrors create an image that is upright and smaller.

75. True or False: Convex mirrors create an image that is upright and smaller.

76. Remember!!!
So remember!
<keep this slide>

77. Law of reflection: when a wave is reflected on a surface, the angle of reflection equals the angle of incidence.
The law of reflection states that when a wave is reflected on a surface, the angle of reflection equals the angle of incidence. We are going to break this down.

78. Regular reflection: reflection of light from a smooth, shiny surface.
A regular reflection is the reflection of light from a smooth, shiny surface.

79. Diffuse reflection: reflection of light from a rough surface
A diffuse reflection is the reflection of light from a rough surface.

80. Concave mirror: a mirror that curves inward
A concave mirror is a mirror that curves inward.

81. Focal point: point where light rays converge to make an image
The focal point is where light rays converge to create an image.

82. Focal length: distance along the optical axis between the focal point and the mirror
The focal length is the distance along the optical axis from the mirror.

83. Convex Mirror: a mirror that curves outward
A convex mirror is a mirror whose surface curves outwards.

84. Thanks for watching, and please continue watching CAPs available from this website.

85. Questions or Comments to Michael Kennedy, Ph.D.
This Video Created With Resources From:
Cooperative Agreement # R324B130023
Curry School Foundation’s Research and Development Fund
Questions or Comments to Michael Kennedy, Ph.D.

86. Activity
Objective: Students will understand the characteristics of convex and concave mirrors. Activity: Students will use a laser and mirror to explore the relationship between the object and image created.
Materials:
Laser pointer
Concave mirror
Ruler
Convex mirror
Wood rod
Resources: