2. Chapter 12.3 Reflection and Color

3. Angle of Reflection = Angle of Incidence

4. Balls bouncing on a pool table follow laws of reflection.

5. Rough surfaces reflect light in many directions, called DIFFUSE REFLECTION

6. When the water is still, reflection is “ clearer ”

13. The image in the convex mirror (left) looks smaller. The images in the concave mirror (right) looks bigger.

15. How Objects React to light Objects can be classified into three categories  Opaque  Transparent  Translucent

16. Opaque Objects Do not allow light to pass through them Examples are brick, carpet, wood, apple, etc. Objects appear the color they are because of the color of light they reflect; all other colors are absorbed

17. Transparent Objects Allow light to pass through them Items are “see-through” Examples are glass and cellophane Objects appear the color they do based on the color/frequency of light they allow to pass through

18. Translucent Objects Allow some light to pass through but scatters most of the light within it Cannot see things clearly through a translucent object Examples are a block of wax or a frosted light bulb

19. R O Y G B I V Red Orange Yellow Green Blue Indigo Violet White light Triangular Prism

20. More on R O Y G B I V Why is the apple red? White light strikes the apple All colors absorbed except red Red light is reflected

21. Still More on R O Y G B I V What color is the apple now? Green light strikes the apple Green light is absorbed. No color is reflected so apple appears black

22. Additive RGB Colors Green Blue Red white Yellow Cyan Magenta http://home.att.net/~B-P.TRUSCIO/COLOR.htm

23. Adding colors of LIGHT

24. CMY-Subtractive Colors Magenta Cyan Yellow black red blue green

25. Pigments – they subtract specific colors of light, so you only see the colors that were not “subtracted”

27. Refraction, or bending of light as it moves from air to water

29. Angles are measured with respect to the line which is perpendicular to the interface. When light travels from one medium--such as air, to another one of higher density--such as water, usually the light ray bends toward the perpendicular line.

33. Total Internal Reflection, as in fiber optic cables.

38. The critical angle for diamond in air is 24.5 degrees; any ray which strikes the surface on the inside at an angle of greater than 24.5 degrees will not escape the diamond.

40. The Convex Lens as a Magnifier