When a body is more than a point, forces can turn it as well as move it. Equilibrium now needs moments to balance too.
Syllabus points covered
- Calculate the moment of a force about a point
- Use the conditions for equilibrium of a rigid body under coplanar forces
- Solve problems involving the equilibrium of rods and laminae
- Locate the centre of mass of a composite body and use it in equilibrium problems
Common mistakes
- Taking moments about a point where an unknown force acts, then including that force anyway.
- Using the length of a rod rather than the perpendicular distance when the force acts at an angle.
- Forgetting that the weight of a uniform body acts at its midpoint.
- Balancing forces but not moments, or the reverse. Equilibrium needs both.
Worksheets
Use these as soon as you've learned the topic and need to practise it. Start with the worksheet, check yourself against the answers, and only then look at the step-by-step solutions.
- Practice worksheetComing soon
- Worksheet answersComing soon
- Step-by-step solutionsComing soon
Topical past papers
Move on to these once you've worked through the worksheets and are ready for harder, exam-style questions. Real past-paper questions on this topic, with the official mark scheme and full worked solutions.
- Topical questions
- Mark scheme
- Step-by-step worked solutionsComing soon
Looking for whole papers by session? All Further Mathematics past papers