Year 9 - Science
Turning forces
Hidden forces
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit explores forces, deformation, Hooke's Law, moments, and work done. It covers pressure in liquids, atmospheric pressure, upthrust, and equilibrium, as well as simple machines and force-extension relationships, highlighting how forces affect motion, friction, and object deformation.
Lesson Summary
You will learn to investigate and calculate the size of turning forces.
Key Notes
- A moment causes turning.
- Moment = force × (perpendicular) distance from the pivot.
- Moments are measured in Newton-metres (Nm).
Vocabulary To Learn
- balanced: A beam is balanced if it is not starting to rotate about its pivot.
- newton-metre: One unit for the turning effect of a force is the newton-metre (N m).
- newton-centimetre: Another unit for the turning effect of a force is the newton-centimetre (N cm).
- moment: The turning effect of a force is called a moment.
Common Mistakes To Avoid
- The turning effect is a force (it is often wrongly called a turning force).
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
A moment causes turning. Moment = force × (perpendicular) distance from the pivot.
2. Define this scientific word and use it in context. 'balanced'
A beam is balanced if it is not starting to rotate about its pivot. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: The turning effect is a force (it is often wrongly called a turning force). Correction: Correct any use of the erroneous term 'turning force' and use examples of the turning effect caused by force with a lever.
More Lessons In This Unit
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