Levers, spanners and gears sim
Pull on a spanner with a newton-meter at different distances and angles and see the perpendicular distance, read the force that turns the nut and work out its moment; drag the pivot of a crowbar or the load in a wheelbarrow; turn a gear pair and watch speed traded for turning effect.
Turning effect of forces · covers the O-Level, IGCSE, GCSE topic
What the sim shows
Model: the moment of a force about a pivot is the force × the perpendicular distance from the pivot to the force's line of action, in N m (distances in m). g = 10 N/kg. Spanner: the nut needs a moment of 0.60 N m to start turning (chosen); each pull strays within ±3 % of that (seeded, so it repeats on every load). The newton-meter reads 0 to 10 N to 0.1 N and can be set with a zero error of +0.2 or −0.2 N. Levers: a 2.0 kg load (20 N); the effort is found from the principle of moments as the load just lifts. Gears: module 4 mm (pitch radius = 2 mm × teeth), each axle has a drum of radius 10 mm, and the load is 300 g (3.0 N). Idealised: no friction apart from the nut's; a light crowbar bar and wheelbarrow (their own weight left out); strings and newton-meters with no mass; strings that do not stretch; a spanner that does not bend; the hand holding each newton-meter is not drawn.
- The part to watch: the spanner, the lever, or the driven gear
- Board, bracket, nut, pivot stand, wheelbarrow, gears, drums, newton-meter
- The line of action of the pull (dashed); the perpendicular distance d⊥ (blue)
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
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