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Physics · Ch 4 · 4.2 Moments · Session 3
Moments & the Principle of Moments
Learn how a force produces a turning effect about a pivot, define the moment of a force, and apply the principle of moments to solve balance problems.
You'll learn to
- ✓ Define moment = force × perpendicular distance
- ✓ State & apply the principle of moments
- ✓ Solve for unknown forces on a balanced beam
Key formula
Moment = F × d⊥ (N·m)
Chapter 4 · Forces & Motion
5 / 11 done4.1 · Forces
Types of forces
Mass, weight & gravity
4.2 · Moments · now
Turning effect of forces
Moments & Principle of Moments
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Centre of mass & stability
4.3 · Stability
Conditions for equilibrium
Does the pivot always have to be at the centre?
No — take moments about any point. The principle still holds: clockwise = anticlockwise moments.
Mr Choolun · Teacher
What units is a moment measured in?
Will this be in Paper 2?
Questions go privately to your teacher.
Moments — summary notes.pdf
3 pages · 480 KB
Worked examples — beams.pdf
5 pages · 1.2 MB
Opens in a secure viewer (watermarked, no download) to protect content.
Knowledge test: Moments
10 questions · ~8 min · earn up to 100 pts
—
Best score
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Attempts
Recommended after watching the session.
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Moments & the Principle of Moments
Physics · Ch 4 · 4.2 Moments
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Moments — summary notes.pdf
Moments — Summary
A moment is the turning effect of a force about a pivot.
Moment = F × d⊥
where F is the force (N) and d⊥ is the perpendicular distance (m) from the pivot to the line of action.
Principle of moments
For equilibrium: total clockwise moments = total anticlockwise moments.
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Moments & the Principle of Moments