--- title: Wheels, axles, ramps and screws — a lesson of Mova's school · trees and pragmatics description: «Wheels, axles, ramps and screws», a lesson of the physics course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: Try turning the thin metal bar inside a door when the handle has come off: it is really hard, yet with the handle on it turns with one fin --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Physics](https://md.mova.elamur.ai/free/en/corpora/school/physics/) / Wheels, axles, ramps and screws # Wheels, axles, ramps and screws Lesson 34 of the physics course of Mova's primary school: 15 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/physics/34-wheels-axles-ramps-and-screws/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/0/) — Try turning the thin metal bar inside a door when the handle has come off: it is really hard, yet with the handle on it turns with one finger; the handle is a wheel and axle, and a big wheel turns a small axle with a much stronger twist. - [1](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/1/) — A ramp is a slope that swaps a big lift over a short distance for a small push over a long distance, which is why a wheelchair goes up a ramp, not a step. - [2](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/2/) — A screw is a ramp wrapped round a rod: each turn creeps it in a little way with a big push, and jar lids and bottle caps are screws too. - [3](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/3/) — A wedge, like an axe head or a door stop, is a ramp that turns one downward blow into strong sideways pushes. - [4](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/4/) — None of these give you something for nothing: you push less, but you push further or turn more times. - [5](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/5/) — A wheel and axle turns a big wheel with a small force into a strong twist on the small axle; door handles, steering wheels, taps and fat screwdriver handles use it. - [6](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/6/) — Old lorries without power steering had huge steering wheels to give the driver more turning force. - [7](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/7/) — A ramp lets you raise something with a smaller push over a longer distance; a steeper ramp is shorter but harder to push up. - [8](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/8/) — Mountain roads zigzag so they are longer but much less steep, and cars and walkers can climb without slipping or straining. - [9](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/9/) — A screw is a ramp wrapped round a rod, and each turn moves it in a little way with a big push. - [10](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/10/) — A wedge, such as an axe head, a door stop or the edge of a knife, turns a push into sideways pushes that force things apart. - [11](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/11/) — On a playground roundabout, a push at the edge turns it more easily than a push near the middle, and riders at the edge move faster. - [12](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/12/) — A rolling wheel or ball has much less friction than a box sliding, which made the wheel one of the most important inventions in history. - [13](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/13/) — A rolling pin presses down on only a thin line of dough at a time. - [14](https://md.mova.elamur.ai/free/en/corpora/school/physics/34-wheels-axles-ramps-and-screws/14/) — A tap's handle turns a screw thread that moves a valve up and down a little, which is why some taps need many turns to open fully. - ← previous: [Levers: lifting heavy things with a little push](https://md.mova.elamur.ai/free/en/corpora/school/physics/33-levers-lifting-heavy-things-with-a-little-push/) - next →: [Pulleys, gears and big machines](https://md.mova.elamur.ai/free/en/corpora/school/physics/35-pulleys-gears-and-big-machines/) - ↑ back to [Physics](https://md.mova.elamur.ai/free/en/corpora/school/physics/)