1. Wave Behavior - Reflection  the bouncing back of a wave after it strikes a barrier.  All waves, sound, light, water, EMS, etc., can be reflected!!  examples: mirror, water wave bouncing back from a pool wall, echo Reflection

2. Wave Behavior –Reflection Cont   Plane mirrors and other smooth surfaces reflect light to form clear images. Incidence Ray Angle of Incidence ------------------- Angle of Reflection Plane Mirrors = Reflected Ray

3. Wave Behavior   the bending of waves caused by a change in their speed as they pass from one medium to another.   More dense the medium, slower the wave Refraction

4. Wave Behavior   Greater the change in speed – more the wave bends.   Ex. light going from air through a convex lens can make images appear larger as the light waves bend.  examples: items in glasses of water, lenses, eyeglasses, telescope, microscope Refraction

5. Refraction with devices   Triangular shaped glass or acrylic that separate white light into its different colors by refracting light waves. Prism

6. Wave Behavior  the spreading out of waves through an opening or around the edge of an obstacle.  examples: water waves around dock or pier, water waves around rock outcrop, sound through a door to a room Diffraction

7. Refraction with devices  Thin piece of material that bends light waves around microscopic slits, creating a rainbow. Diffraction Grating

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10. Wave Behavior  Absorption --- this occurs  Absorption --- this occurs when the energy is not transferred through, or reflected by the given medium. The energy enters the medium and does not exit.   Objects or substances that absorb any wavelength of electromagnetic radiation become warmer and convert the absorbed energy to infrared radiation.

11. Wave Behavior   Transmission of waves occurs when waves pass through a given point or medium. Sound waves are transmitted through solids, liquids, and gases. Light waves can travel through some materials but not others.

12. Interaction of Light Waves with Materials TransparentTranslucent  Most of the light passes through these materials. Examples: Air, water, clear glass. Uses: light bulbs, clock faces, window glass   These materials will transmit some light, but cause it to be scattered so no clear image is seen. Objects viewed through translucent materials can be seen, but not clearly. Examples: frosted windows, notebook paper.

13. Opaque  No light passes through these materials.  The materials will either reflect light, absorb light, or both.  Examples: wood, mirrors, metal, fabric, etc. Interaction of Light Waves with Materials

14. Creating a View on the World 1.Position your index card in a horizontal position. Draw a line across the top 3 cm from the top and across the bottom 3 cm from the bottom. 2.Create three, 3 cm x 3 cm boxes along the drawn lines on the card. 3.Place a piece of transparent, translucent and opaque material across the opening. 4. Label each box with the type of material marker. transparent translucentopaque

15. Why Humans See the Color We See ColorWhiteBlack  Is determined by the wavelength being absorbed or reflected.  An object will appear to be a certain color because it is reflecting that color. Example: A shirt that is red is reflecting the red wavelength but absorbing all others.  Reflects all colors in visible light.  Absorbs all colors in visible light.

16. Why we see color Colored Filters   allow only certain colors of light to pass/transmit through them; they absorb or reflect all other colors. Ex. a blue filter only transmits blue light. Objects seen through a blue filter will look blue if the objects reflect blue; objects of other colors will appear black because the other color wavelengths are being absorbed by the filter. Let’s experiment with filters:   http://micro.magnet.fsu.edu/pri mer/java/primarycolors/colorfilte rs/index.html http://micro.magnet.fsu.edu/pri mer/java/primarycolors/colorfilte rs/index.html