A student uses a spanner to tighten a bolt. The student pushes on the end of the spanner handle with a force. Explain how using a longer spanner handle makes it easier to tighten the bolt, and state the principle that determines whether the bolt will turn.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
A spanner is a type of lever. The bolt acts as the pivot point. The student applies a force at the end of the handle.
Model answer (4 marks)
A longer handle increases the distance from the pivot, so for the same applied force the moment (turning effect) is larger. A larger moment gives a greater turning effect on the bolt, making it easier to tighten. The bolt will turn when the total clockwise moment equals the total anticlockwise moment about the pivot – the principle of moments.
Examiner tips
- Use the term "moment" and relate it to force and distance
- Explain that a larger moment gives a greater turning effect
- Mention the principle of moments and the equality of clockwise and anticlockwise moments
- Keep the answer concise and to the point
Common mistakes
- Confusing torque with force, or omitting the distance factor
- Failing to state the principle of moments or the equality of moments
- Using vague language such as "more force" instead of "larger moment"
Mark scheme (4 marks)
- The moment (turning effect) depends on both the force applied and the distance from the pivot
- A longer handle increases the distance from the pivot (bolt), so the moment is larger for the same applied force
- A larger moment means a greater turning effect on the bolt, making it easier to tighten
- The principle of moments states that the bolt will turn (or be in equilibrium) when the total clockwise moment equals the total anticlockwise moment about the pivot
Related
- All Eduqas GCSE Physics revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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