Moments, levers, gears and equilibrium

By the end you’ll be able to

• Calculate the moment of a force about a pivot using $$\text{moment}=\text{force} \times \text{perpendicular distance}$$.
• Apply the principle of moments to balanced objects and equilibrium situations.
• Explain the difference between stable, unstable and neutral equilibrium in terms of centre of mass and the line of action of weight, where required by the specification used.