Science at key stage 3 (Year 7)
Unit 7K: Forces and their effects
Section 8: a. What does friction do?
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Objectives |
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- that friction is a force which opposes motion
- how friction between two surfaces can be reduced with a lubricant
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Activities |
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Outcomes |
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Children: |
- Remind pupils of the experiments they did at the beginning of the unit and ask them why the wooden block and ice cube or string and plastic thread behaved differently. Carry out some quick demonstrations,
eg oiling a wheel, to illustrate the importance of lubricants, and ask pupils to explain how the lubricants work.
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- explain differences in behaviour in terms of differences in frictional forces
- identify characteristics of lubricants,
eg often liquid,
smooth, and explain their action,
eg smooth out rough surfaces
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Points to note |
- Pupils are likely to have had many experiences of controlling variables in key stage 2, although they may not have used these terms. However, they may find it difficult to distinguish between quantities they need to keep constant and those that are not relevant.
- In key stage 2 pupils are likely to have investigated friction by dragging shoes or weighted containers across different surfaces. If so, they should be encouraged to investigate other factors,
eg weight, surface area, effect of lubricant such as water.
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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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