This definitions covers Key Definitions within Moments & Levers for GCSE Physics. Revise Moments & Levers in Forces for GCSE Physics with 13 exam-style questions and 10 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 8 of 14 in this topic. Make sure you can use the exact wording confidently, because definition marks are often lost through vague language.
📖 Key Definitions
Moment: The turning effect of a force about a pivot. Moment = Force × perpendicular distance from pivot. Unit: Newton metres (Nm).
Pivot (fulcrum): The fixed point about which a lever rotates.
Principle of moments: For a body in equilibrium (balanced), the sum of clockwise moments equals the sum of anticlockwise moments about any pivot.
Equilibrium: A state of balance where the resultant force is zero AND the resultant moment is zero — object does not accelerate or rotate.
Lever: A simple machine using a rigid bar and pivot to multiply force at the expense of distance.
Practice questions for Moments & Levers
What is a moment?
State the principle of moments.