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How does a pulley change the direction of a pulling force?

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A diagram displays six types of simple machines with labeled illustrations: inclined plane, wedge, screw, lever, wheel and axle, and pulley, each shown with real-world examples like ramps, axes, screws, seesaws, door handles, and pulleys lifting objects. — simple machine Six simple machines for transforming energy into work.

A pulley is a simple machine consisting of a wheel with a grooved rim that carries a flexible rope, cable, or chain.12

It changes the direction of a pulling force by using its grooved rim to redirect the path of the rope or cable. When used as a single, fixed pulley, the device allows an operator to exert a force in a different direction—such as pulling downward to lift a weight upward—thereby changing both the direction and the point of application of the force. When multiple pulleys are combined into a block and tackle, they can be used to further augment pulling force and lift heavy loads.314