--- title: "Levers, Pulleys & Gears" description: "Recognise that some mechanisms including levers, pulleys, and gears allow a smaller force to have a greater effect" canonical: https://lightmysky.com/learn/science/levers-pulleys-and-gears-mt_Q2k3fSwyzQ source: https://lightmysky.com/learn/science/levers-pulleys-and-gears-mt_Q2k3fSwyzQ.md retrieved: 2026-10-19 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Levers, Pulleys & Gears Recognise that some mechanisms including levers, pulleys, and gears allow a smaller force to have a greater effect Subject: Science · Area: Forces & Motion · Ages 9 to 10 Page: https://lightmysky.com/learn/science/levers-pulleys-and-gears-mt_Q2k3fSwyzQ ## Ready when they can - Describe a lever's effort, load and pivot, and explain how their positions affect lifting - Explain how a pulley changes the direction of a force and can make lifting easier - Describe how matching gear teeth pass on turning and change its speed, direction or turning effect ## Lesson: Levers, Pulleys, and Gears A force is a push or a pull. You have seen how forces change motion. Mechanisms can change a force's direction or help you move a load with less force. The force you apply is the effort. Effort can be a push or a pull. A machine does not make energy. *(drawing: This example compares the force needed for the same load. The lever uses a longer effort arm and a shorter load arm.)* **Example.** A lever uses a stiff bar that turns around a pivot, also called a fulcrum. The bar must resist bending when effort is applied. Effort is your applied force; the load is what you move. Mia and Cole sit on opposite sides of a seesaw's pivot. When Mia's end moves down, Cole's end moves up. Mia supplies the effort and Cole is the load. Other levers can have effort and load on the same side of the pivot. **Example.** A flagpole has a fixed pulley: its wheel stays at the top. Pull the rope down and the flag rises. This changes the pulling direction, so you can work from the ground. Ignore friction and the rope's weight. To raise a load at steady speed, the pull equals its weight because one rope section supports it. Starting it moving upward needs a little extra force. Gears are toothed wheels. Matching teeth fit together and pass on turning. Two gears touching at their outer edges turn opposite ways. With matching tooth sizes, a bigger gear has more teeth. A small gear driving a big one makes it turn slower; a big gear driving a small one makes it turn faster. Ignore friction: the bigger driven gear has a greater turning effect at its axle, not a greater push between the teeth. A movable pulley rises with the load. In our ideal examples, ignore friction and the weights of the rope and pulleys. Each section of the same rope pulls equally. At steady speed, two vertical sections supporting the moving load each carry half its weight, so your pull is half the weight. Count supporting sections, not wheels. Extra fixed wheels can redirect the rope without reducing the pull. **Example.** In the chart's lever example, ignore friction and the bar's weight. Mia pushes farther from the pivot than Cole sits. At steady speed, lifting Cole takes 10 force units directly or 4 with this lever. His weight stays the same. Mia's end travels farther than Cole's end. Moving the pivot closer to a load can reduce the effort. On an equal-arm seesaw, a larger downward force gives a larger turning effect. A force chart compares the force needed in different arrangements. Read the label to find the arrangement you need, then read its value. To find how many fewer force units one arrangement needs, subtract its value from the larger value. If direct lifting needs 9 units and a lever needs 3, the difference is 9 - 3 = 6 units. **Recap.** Levers can reduce lifting force. Fixed pulleys change pulling direction; movable systems can reduce force. Gears change turning speed, direction or turning effect. ## Practice 24 questions on this page, each with its working shown. ## Needs first - [Balanced & Unbalanced Forces](https://lightmysky.com/learn/science/balanced-and-unbalanced-forces-mt_3WMADSy0mA) - [Gravity & Falling Objects](https://lightmysky.com/learn/science/gravity-and-falling-objects-mt_AvrQauS_zX) - [Force & Motion Vocabulary](https://lightmysky.com/learn/science/force-and-motion-vocabulary-mt_F3ATPTCYm6) ## Opens up - [Mechanisms That Make Things Move](https://lightmysky.com/learn/design-and-technology/mechanisms-that-make-things-move-mt_i6Je5hnxJz) - [Moments, Pressure & Hooke's Law](https://lightmysky.com/learn/science/moments-pressure-and-hookes-law-mt_vuNjYx3qOy)