Chapter 4
Turning effects of forces
A force can make an object turn.
Learn to choose the perpendicular distance, account for each turning effect and explain how an object balances.
Includes moments, equilibrium, centre of gravity and stability. For K323 (2027) / 6091 (2026).
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Moments and perpendicular distance
Identify the pivot and force line, then calculate the turning effect and its direction.
Balancing moments
Include all the forces when applying the principle of moments, including the object's own weight.
Centre of gravity
Represent an object's weight at one point and locate that point using suspension lines.
Stability and toppling
Use the weight's line of action to explain the effects of centre-of-gravity height and base width.