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πŸš€ Inventions and machines πŸ”§ Machines and tools

The pulley

The pulley

πŸ“– In short

A pulley is a wheel with a rope or belt around it, a simple machine that helps us lift heavy things. We see it over a well, where we pull up the bucket, on huge cranes at building sites and on flagpoles.

🀩 Did you know?

  • The pulley is one of the six simple machines.
  • If both pulleys are the same size, the only benefit is changing the direction of the force.
  • Stories say Archimedes used pulleys to pull a big ship by himself.
  • Huge building cranes use lots of pulleys.

πŸ”Ž Find out more

🌟 It changes the direction of force

With one fixed pulley you pull the rope down and the load goes up. That's easier because you use your body weight to pull.

πŸ” More pulleys, more force

When we use several pulleys together, we can lift very heavy loads with a small effort, but we have to pull a longer rope.

πŸ’‘ Everywhere

We find pulleys in lifts, cranes, ships' sails, window blinds, gym machines and even car engines, where belts turn different parts.

🎯 The water well

Old wells in villages and oases had a wooden pulley above them with a rope tied to a bucket, so people could pull up water easily.

🧩 Test yourself

1 What goes around a pulley?

2 How can we lift a heavier load with less effort?

3 Which picture shows β€œThe pulley”?

πŸš€ Discover more

πŸ“· Picture sources: Wikimedia Commons