A student uses a door handle to open a heavy door. The door handle is positioned far from the hinge. Explain why positioning the handle far from the hinge makes it easier to open the door.

AQA GCSE Physics (8463) — 4.5.4 Moments, levers and gears (Phys only) · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

The hinge is the pivot.
A moment is produced when a force is applied to the handle.
Moment = force × perpendicular distance from the hinge to the line of action of the force.
A larger perpendicular distance gives a larger moment for the same force, so less force is required to open the door.

Examiner tips

  • Use the word "pivot" for the hinge. State the moment formula explicitly. Explain that a larger distance gives a larger moment. Show the logical link to less force needed.

Common mistakes

  • Confusing the hinge with the door handle. Forgetting to mention the perpendicular distance. Using the wrong formula (e.g. force × distance without specifying perpendicular).

Mark scheme (4 marks)

  1. The hinge acts as the pivot (point of rotation)
  2. A moment (turning effect) is created when a force is applied to the handle
  3. Moment = force × perpendicular distance from the pivot to the line of action of the force
  4. A greater perpendicular distance means a larger moment is produced for the same applied force, so less force is needed to open the door

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