Science at key stage 3 (Year 8)
Unit 8K: Light
Section 2: b. How does light travel?
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Objectives |
| Children should learn: |
- to interpret evidence and draw conclusions from it
- that light travels in a straight line
- that the path of light can be represented by rays
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Activities |
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Outcomes |
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Children: |
- Carry out a range of quick activities designed to develop the idea that light travels in straight lines,
eg producing a shadow from a strong source, trying to look down a piece of rubber tubing, showing images of light rays shining through clouds, light rays in a mist, spotlight beams, light beams being reflected in a mirror. Encourage pupils to try to explain these phenomena in terms of a sequence beginning with light leaving the source and finally hitting a screen. Help pupils to use the idea of light travelling in straight lines in their explanation.
- Demonstrate how we can test the idea by shining a beam of light through a series of holes in pieces of card arranged one behind the other. Reinforce this concept by showing a laser beam and sprinkling talc or chalk dust in its path.
- Introduce the use of rays to represent light and ask pupils to draw diagrams of the evidence they have seen, using such lines to show the path taken by light in each case.
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- describe evidence to support the idea that light travels in a straight line
- represent simply the path of light as rays
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Points to note |
- In key stage 2 pupils will have explored rays and beams of light. They are less likely to have produced explanations for phenomena in terms of light travelling in straight lines, or to have constructed ray diagrams.
Safety
- lasers should be class 2 and obtained from a reputable supplier. Laser pointers are usually class 3 and so are unsuitable
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This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
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