1. Colour
D. Crowley, 2008

2. Colour In the back of your books:
To know how we see colour
In the back of your books:
Explain as clearly as you can, how a rainbow is formed.
Key words: droplet, sunlight, refraction, bends, colour

3. Dispersion
Complete the spectrum worksheet

4. Dispersion

5. Seeing How do we see a non-luminous object, such as a book?
Light from the luminous object hits the non-luminous object,
reflecting light into our eye

6. Colour How do we see different colours? Why does a red dress look red?
Why does a green apple look green?
Colours are made by mixing other colours of light
Coloured objects reflect some colours and absorb others

7. Absorbing & Reflecting
Coloured objects reflect some colours and absorb others
For example
A red dress absorbs all colours except red, which it reflects
A green apple absorbs all colours except green, which it reflects
What about black and white?
Objects appear white if they can reflect all the colours of the spectrum
Objects appear black if they absorb all the colours of the spectrum

8. Colours green red magenta blue yellow cyan
The three primary colours of light are: red, green, and blue
yellow
red
green
magenta
cyan
blue
Secondary colours may be made by mixing two primary colours together – these are: magenta, yellow, and cyan

9. Colours

10. Task
Your task is to draw a ray diagram of how we see different colours, such as the balls on a snooker table
Draw a ray diagram showing how we see a red ball and green ball
Then show how we see a magenta ball
Finally show how we see a white ball and black ball (think about this)!
Red

11. Colours
Green
Magenta

12. Colours White No light is absorbed (all reflected) Black
All light is absorbed (none reflected)

13. Colours

14. Quiz