A simple machine helps make work easier by changing the amount or direction of the force being applied. There are six main types of simple machines that can be used to increase efficiency or change the direction of a force.
Inclined Plane
An inclined plane is a flat sloped surface used to produce a mechanical advantage by allowing the user to exert their input force over a longer distance.
Wedge
Wedges are a simple machine that are thick at one end and taper to a thin edge. A wedge can be thought of as two inclined planes back to back.
Screw
Screws are composed of an inclined plane wrapped around a cylinder. The closer the threads are on a screw, the greater the mechanical advantages.
Levers
A lever is a bar that pivots, or rotates, on a fixed point. Levers can be used to change the direction of the input force.
Wheel and Axle
The wheel and axle is a simple machine that consists of two cylindrical objects fastened together. The larger of the two is called the wheel and the other the axle.
Pulley
Pulleys are simple machines made up of a grooved wheel with a rope or cable wrapped around it. A pulley can be used to change the direction of the input force or produce a mechanical advantage.