1. Light can be reflected, absorbed or transmitted by objects

2. Light travels in straight lines:
Properties of Light
Light travels in straight lines:
Laser
To show the direction in which it travels we use an arrow, called a ray.

3. Light travels VERY FAST – around 300,000 kilometres per second.
At this speed it can go around the world 8 times in one second.

4. Light travels much faster than sound. For example:
Thunder and lightning start at the same time, but we will see the lightning first.
2) When a starting pistol is fired we see the smoke first and then hear the bang.

5. We see things because they reflect light into our eyes:

6. Absorption White paper looks white because it reflects light
Black print on white paper looks black because it does not reflect any light
Instead black absorbs all the light energy and coverts it to heat
What colour of clothes do you wear on a hot day? Why?
What about on a cold day? Why?

7. Transmission
Different materials allow different amounts of light to pass through them.
For example – how does light pass through glass?
It passes through because the glass is transparent
glass

8. Transmission
If only some of the light travels through the material but some is scattered then the material is translucent
Wax paper

9. Transmission
If none of the light travels through the material then it is opaque
Brick wall
(Some light can also be reflected – that’s why we see opaque objects!)

10. Shadows
Shadows are places where light is absorbed by objects that are opaque