Unit 2 Optics

Chapter 4 Many properties of light can be understood using a wave model of light.

4.2 Properties of Visible Light pg 148


4.2 Color and Reflection
Reflection occurs when a light wave strikes and object and bounces off. when sunlight strikes coloured clothing, some colours are reflected while other colours are absorbed. only the refleced colours can be seen. Bright coloured shirts look dark in a room because shirts don't make their own light. So in a dark room a brigh coloured shirt would look bright. the 3 colours red, green and blue are needed to produce the colours of the rainbow. The colours red, green and blue are sometimes called additive primary colours because adding all three together in proper amounts will make white light. The light of two additive primary colours will produce secondary colours yellow, cyan and magenta.
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1. Why do we only see a certain color when looking at objects?
We only see certain colours because it reflects one colour and absorbs other colours.
2. When does a reflection occur?
Reflection occurs when a light wave strikes an object and bounces off.
3. What three colors make white when mixed with an equal amount of each?
The colours red, blue and green make white.
4. What happens when sunlight strikes colored clothing?
The coloured clothing will reflect that colour and absorb the other colours.
5. What are the three secondary colors?
The 3 secondary colours are cyan, yellow and magenta.
6. Why does a bright red shirt look black when it is placed in a dark room?
A shirt does not produce its own light, but merely reflects the light in the room, the shirt appears to be black when there is no source of light.
7. How many colors are need to produce all the colors of the rainbow?
7 colours:red, orange. yellow. green, blue, indigo, violet.
8. What are sometimes called the Additive Colors?
Red, green and blue are sometimes called the additive colours because adding all three of these together make white light.
9.What colours make the secondary colours?
Blue and green make cyan, red and green make yellow and red and blue make magenta.
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Links:
Reflection

Pictures:
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Primary and Secondary Colors
external image lake_reflections_T3928.jpg external image PictureReflection.png

Assignment: Reflections. February 16, 2003
Assignment: Reflections. February 16, 2003