1. 28 May 2018
Seeing the light
Please stick in your quiz results, complete the target sheet by adding your score and colouring in the objectives.

2. First ideas
In medieval times people thought that our eyes sent out rays that hit objects and returned with information – some people still do!
Now we believe that light comes from a luminous source such as the Sun, stars or a light bulb, not our eyes

4. Travelling at the speed of light
The light that leaves a bulb travels outwards in all direction at a speed of m/s
This is so fast it seems instantaneous

5. Question (Level 4)
When you switch on a light, why can you not tell that light hit closer objects before objects further away?

6. Worked example
The Sun is about m away from Earth. How long does it take for light from the Sun to reach us?
REMEMBER: speed = distance / time

9. A model for light Scientists use models to describe light
One model uses rays and ray diagrams to show the path light takes
Only the important rays are drawn

10. Worked example
Draw a ray diagram (pencil and ruler) to show a girl in a room with a window as the only light source looking at a clock

12. Travelling through glass
Most materials are opaque – light does not travel through them. The materials ‘soak up’ the light in a process called absorption
Glass allows light to travel through it – this is called transmission
If the light travels through in straight lines the material is said to be transparent

13. transparent

15. translucent

17. 6.2 Seeing the light Questions
Name two luminous objects.
Use the particle model to explain why a yellow bucket, seen in yellow light, looks yellow.
Use the particle model to explain why a white car looks white.
Use the particle model to explain why a black snake looks black.
If you shine green light onto a red card, the card appears black. Explain why.
(Level 4)
(Level 4)
(Level 5)
(Level 6)
(Level 7)
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18. 6.2 Seeing the light Questions
Draw a ray diagram to show what happens when a torch lights up a cup and saucer and you see both.
Suppose you have a torch with a filter that blocks only red light and another torch with a filter that blocks every colour except red. You shine the torches at the same point on a sheet of white paper. What colour does the paper seem to be?
(Level 8)
(Level 8)
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