SIMPLE MACHINES Is a mechanical device that multiplies, and changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that provide mechanical advantage.
These simple machines fall into two classes: (I.) the inclined plane, wedge, screw characterized by the vector resolution of forces and movement along a line, and (II.) the lever, pulley, and wheel and axle are characterized by the equilibrium of torques and movement around a pivot.
INCLINED PLANE An inclined plane is a straight ramp and is used for moving loads up and down the hill It is a flat surface that lies at an angle relative to level ground used to form a ramp to raise and lower a load.
WEDGE A wedge is a triangular shaped round tool and is used to separate two objects or portions of an object, lift an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular (normal) to its inclined surfaces
SCREW A screw is a mechanism that converts rotational motion to linear motion, and a torque (rotational force) to a linear force. The most common form consists of a cylindrical shaft with helical grooves or ridges called threads around the outside.
LEVER A lever is constructed from a beam attached to ground by a hinge, or fulcrum. A lever amplifies an input force to provide a greater output force, which is said to provide leverage.
PULLEY A pulley is a wheel on an axle that is designed to support movement of a cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power.
WHEEL AND AXLE A wheel and axle is a simple machine made up of two circular objects of different size. The axle (a small wheel) is attached to the center of a larger wheel. All wheels need an axle. The wheel and axle must move together to be a simple machine. A wheel and axle lifts or moves loads.