THE TURNING EFFECT OF FORCES

2 marks · Normal

Explain why it is easier to loosen a tight bolt using a spanner with a long handle rather than a short one.

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A longer handle gives a greater perpendicular distance from the pivot, so for the same force, the moment (turning effect) is larger. This makes it easier to produce enough turning effect to loosen the bolt.

Must show: reference to increased perpendicular distance, increased moment or turning effect for same force

Also accept: It increases leverage so less force is needed

Common mistakes: Just 'longer handle gives more force' (needs moment/turning effect focus)

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Marking points

B1 · 1 mark · Mentions increased distance (or leverage)

B2 · 1 mark · Clearly links to larger moment/turning effect for given force

Worked solution

A long handle increases the perpendicular distance from the pivot (the centre of the bolt). Since moment = force × distance, the same force produces a larger moment if the distance is greater, making it easier to overcome the tightness of the bolt.