--- title: Simple machines and how they help — a lesson of Mova's school · trees and pragmatics description: «Simple machines and how they help», a lesson of the world course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A simple machine is a tool that makes a job easier by changing how much force we need or which way we push. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/) [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/) / [World](https://md.mova.elamur.ai/free/en/corpora/school/world/) / Simple machines and how they help # Simple machines and how they help Lesson 52 of the world course of Mova's primary school: 20 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/world/52-simple-machines/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/0/) — A simple machine is a tool that makes a job easier by changing how much force we need or which way we push. - [1](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/1/) — The lever, the wheel and axle, the pulley and the ramp are simple machines. - [2](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/2/) — A lever is a stiff bar that turns around a point called the pivot. - [3](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/3/) — If you push far from the pivot, a small force can lift a heavy load that sits close to the pivot — that is how a long crowbar lifts a big stone. - [4](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/4/) — Machines do not give us free work: to use less force we must push over a longer distance. - [5](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/5/) — Walking up a long gentle ramp is easier than climbing a steep ladder, but the path is longer. - [6](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/6/) — A wheel and axle is a big wheel fixed to a thin rod; turning the big wheel a long way turns the axle with a strong force, as in a door knob or a steering wheel. - [7](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/7/) — Wheels also roll, which makes much less friction than dragging. - [8](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/8/) — A pulley is a wheel with a rope over it. - [9](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/9/) — One fixed pulley changes the direction of the force, so you can pull down to lift up; several pulleys together let a small force lift a heavy load with a longer pull of rope. - [10](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/10/) — A simple machine makes work easier by changing the size or the direction of a force. - [11](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/11/) — A lever is a bar that turns around a pivot. - [12](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/12/) — The further from the pivot you push, the less force you need to lift a load. - [13](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/13/) — A see-saw, scissors, a bottle opener and a wheelbarrow all use levers. - [14](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/14/) — A ramp lets you lift a load with less force by moving it along a longer path. - [15](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/15/) — A wheel and axle turns a small force on a big wheel into a stronger turn on the thin axle. - [16](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/16/) — Rolling on wheels makes much less friction than dragging along the ground. - [17](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/17/) — A single fixed pulley changes the direction of the pull but not its size. - [18](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/18/) — Several pulleys together let you lift a heavy load with a smaller force but a longer pull of rope. - [19](https://md.mova.elamur.ai/free/en/corpora/school/world/52-simple-machines/19/) — A machine that saves force always makes you move further; it never saves work for free. - ← previous: [Forces — pushes, pulls, friction and magnets](https://md.mova.elamur.ai/free/en/corpora/school/world/51-forces/) - next →: [Light, shadows and colours](https://md.mova.elamur.ai/free/en/corpora/school/world/53-light/) - ↑ back to [World](https://md.mova.elamur.ai/free/en/corpora/school/world/)