Simple machine

A simple machine is a basic mechanical device that changes the magnitude or direction of a force. Its ideal operation trades force for distance rather than reducing the work required.

Work (physics): The energy transferred when a force moves an object through a distance. In an ideal machine, increased output force is balanced by increased travel distance.
Wheel and axle: A large wheel fixed to a smaller axle so both rotate together. Their different radii can convert a modest input force into a larger output force.
Block and tackle: A pulley system using multiple sheaves and a continuous rope to lift a load. It combines pulleys to reduce the input force needed for lifting.
Compound machine: A device made from two or more simple machines working together. It combines basic mechanisms, as scissors combine levers and wedges.
Lever: A rigid bar that rotates around a fixed point called a fulcrum. Its arms determine how input force becomes output force.
Wedge: A tool with sloping sides that converts force applied at its blunt end into separating forces. It redirects an applied force to split, cut, or hold materials apart.
Ramp: A sloped surface that provides a route between different heights. A ramp is an inclined plane used to move loads with less force over more distance.
Perpetual motion machine: A hypothetical machine that would operate indefinitely or produce useful work without an energy source. Simple machines cannot create energy, despite their ability to multiply force.
Pulley: A wheel with a grooved rim that guides a rope or cable. A fixed pulley redirects force; a movable pulley can also multiply it.
Screw: A helical ridge wrapped around a cylinder or cone. It is an inclined plane wound around an axis, converting rotation into linear motion.

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Ancient technologyNarrower topic: Simple machines explain how modest tools amplified human and animal effort.