The pulley is a wheel which forms part of a simple machine that can be used to make lifting heavy objects easier. Its mechanical advantage is equal to the number of wheels used.
A pulley is a wheel combined with ropes and other wheels in a block to make heavy things easier to lift. These rope and pulley systems are often known as a block and tackle. A block and tackle was identified as one of the simple machine. A pulley system is used to lessen the effort it takes to lift a load. The more pulleys that are used in the system the easier it will be to lift an object.
Pulleys have been in existence for a long time, some of the earliest pulleys found were in Mesopotamia where they were believed to be used to lift containers of water. The simple pulley allowed ancient peoples to raise large stone structures, develop ships with sails to go long distances, and load carts and boats with heavy goods. Pulleys revolutionized construction, sea travel, and trade.
Pulleys are used in a wide range of different situations, from raising a washing line, to raising sails on a sailing ship, to cranes that are used to lift huge sections of skyscrapers. Since their invention, pulleys have allowed humans to lift things that we simply wouldn’t be able to lift without machinery.