pulley

Everyday

A pulley is a simple machine made of a wheel with a groove that a rope or chain runs over, used to lift heavy things more easily. tree →

In the lessons

In science lessons a pulley is one of the simple machines: pulling down on the rope lifts a load up; using more pulleys means you need less effort but must pull more rope. Flagpoles, cranes and wells use pulleys. Phrases: «a pulley system», «block and tackle», «simple machines».

Examples

• We used a pulley to lift the bucket. tree →
• The flag goes up the pole with a pulley. tree →
• A crane uses pulleys to lift heavy loads. tree →
• With two pulleys, you need less effort. tree →
• The old well had a pulley and rope. tree →
• We built a pulley in our science lesson. tree →
• The curtains open with a small pulley. tree →
• Off went Tom and four men besides, and when they came to the tree they began to draw it into the cart with pulleys. tree →

Note

Countable; plural pulleys (not pullies). Simple machines: lever, pulley, wheel and axle, inclined plane, wedge, screw. Maths of pulleys: with more ropes holding the load, the effort is smaller but the distance you pull is longer.