1. Light
Chapter 47

2. Light Light is a form of Energy because it can make things move.
Examples:
Crooke’s radiometer
Solar powered calculator.

3. Light travels in straight lines.
Experiment to show that light travels in straight lines.
If the middle card is moved the light cannot be seen.

4. Shadows
Shadows can be explained by the fact that light travels in straight lines.
A shadow is total or partial darkness behind an object blocking the light.

5. Solar Eclipse One of the most spectacular shadows is the
solar eclipse where the moon passes
between the earth and the sun.

6. Reflection
Light bounces off or reflects off a surface. A shiny polished surface (a mirror) reflects rays of light in a regular orderly manner.

7. A Periscope
A periscope is an example where light rays are reflected off mirrors.
The mirrors are positioned at 45’ angles. The light rays reflect off the top mirror, down to the bottom mirror and then to the eye.

8. Refraction
Refraction is the bending of light as it passes from one medium to another.
The light ray gets pulled towards the denser substance.

13. Lenses Lenses refract or bend light passing through them.
Convex Lens (converging lens)
Concave Lens (Diverging lens)

15. Convex lens(converging lens)

16. Concave Lens(Diverging lens)

17. Colour
Dispersion of white light is the breaking of white light into its colours.
The prism disperses the white light into different colours.

18. Dispersion
A good example of dispersion is a rainbow.

19. Newton’s disc

20. Primary Colours
The primary colours of light are Red Green and Blue. These combine to give white light.
Secondary colours are formed by mixing any two primary colours together.
Red Green = Yellow
Green + Blue = Cyan
Blue Red = Magenta

21. Action of the eye