Moments, Levers and Gears: M = Fd and the Principle of Moments | GCSE Physics

Moments for GCSE Physics (separate Physics only), animated with worked examples: why a door handle sits far from the hinges, and the moment of a force, M = Fd, with d the perpendicular distance from the pivot (a spanner: 20 N at 25 cm gives 5.0 N m, and why a slanted push turns less). The principle of moments on a see-saw (where must a 750 N adult sit to balance a 300 N child at 2.0 m?) and on a metre ruler with two weights on one side (find the unknown weight: 2.0 N). Levers as force multipliers: a crowbar turns a 50 N push into 450 N on a rock. Gears: a 10-tooth gear driving a 30-tooth gear turns it a third as fast, the other way, with three times the moment. Finishes with four mistakes that cost marks. Covers: AQA 4.5.4 · Edexcel Topic 9 (9.6P–9.9P) · OCR Gateway P2.3k–m (separate Physics only on all three boards, Foundation and Higher; not in Combined Science). 0:00 Intro 0:08 Hook 0:42 The moment of a force 1:52 The principle of moments 3:06 Worked example: two moments on one side 4:40 Levers 5:36 Gears 6:41 Common mistakes 7:18 Summary Narrated with an AI voice. Worked Example is not affiliated with or endorsed by AQA, OCR or Pearson Edexcel. Exam board names are used only to show which specifications a video covers.