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Pulleys. What is a pulley?. A grooved wheel with a rope or chain running through it. Fixed Pulleys. A pulley supported by something that does not move, such as a ceiling, wall, or tree. Movable pulleys. A pulley attached to something moveable, often a rope. Block and Tackle.
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What is a pulley? • A grooved wheel with a rope or chain running through it.
Fixed Pulleys • A pulley supported by something that does not move, such as a ceiling, wall, or tree.
Movable pulleys • A pulley attached to something moveable, often a rope.
Block and Tackle • A combination of fixed and movable pulleys often used to move heavy loads. Increasing the number of pulleys used can increase the mechanical advantage.
Mechanical Advantage A single fixed pulley will only change the direction of the force required to move an object. (ex. Flagpole)
Mechanical advantage • As a movable pulley is added, the mechanical advantage increases. Less force is required to move the object, but the distance required to move the object increases.
Mechanical advantage. • The rope wraps around the movable pulley a second time, increasing the mechanical advantage.
Mechanical Advantage • The number of cords that SUPPORT the load (pass underneath the pulley)