Levers, Pulleys & Gears
Recognise that some mechanisms including levers, pulleys, and gears allow a smaller force to have a greater effect
What a learner can do afterwards
- Describe how a lever works: effort at one end moves a load at the other, with a pivot in between
- Explain how a pulley changes the direction of a force and can make lifting easier
- Describe how gears transfer and change the size or direction of forces
The lesson
You already know that a force can push or pull something. Some tools change how that force works, so a small push can do a big job. Levers, pulleys, and gears are simple machines that do exactly this.
Mia sits on one end of a seesaw, and her friend Cole sits on the other end. The middle point, where the seesaw balances, is the pivot. When Mia pushes down with her weight, that is the effort, and it lifts Cole up on the other side, which is the load.
Every day, a flag gets raised using a pulley at the top of the pole. Pulling the rope down on one side makes the flag go up on the other side. The pulley does not make the pull weaker. It just changes the direction, so pulling down can lift something up.
Gears are wheels with teeth that lock together. When one gear turns, its teeth push the next gear's teeth, so the turning passes on. A small gear turning a big gear can change how fast something spins or how hard it pushes.
Levers, pulleys, and gears all change how a force works, so a smaller effort can move or lift something bigger.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.