Moments, Levers and Gears

This lesson covers the turning effect of forces — known as moments — and how levers and gears act as force multipliers. This is part of the Edexcel GCSE Physics specification (1PH0), Topic 2: Motion and Forces. You need to be able to calculate moments, apply the principle of moments, and explain how levers and gears work.

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What Is a Moment?

A moment is the turning effect of a force about a pivot (also called a fulcrum). When you push a door handle, turn a spanner, or use a see-saw, you are applying a moment.

The moment of a force is calculated using:

Moment = Force × Perpendicular Distance from the Pivot

M = F × d

Quantity	Symbol	Unit
Moment	M	Newton-metres (Nm)
Force	F	Newtons (N)
Perpendicular distance from pivot	d	Metres (m)

Key Points