Six Simple Machines

• Lever

• Wheel and Axle

• Inclined Plane

• Wedge

• Screw

• Pulley

Lever

A lever is a straight or curved rigid bar that is free to turn about a fixed point.

All levers have three location of interest:

• Fulcrum or Fixed Point

• Point of Effort where work is done on the lever

• Load which is being moved

Classes of Lever

• Class 1 Lever

• Class 2 Lever

• Class 3 Lever

Class 1 Lever

has fulcrum located between effort and load. Class 1 lever includes crowbar, scissors, and pliers.

Class 2 Lever

has the load between the effort and load. The effort and resistance move in the same directions. Examples of class 2 levers are wheel barrows, bottle opener, and nutcracker.

Class 3 Lever

has the effort between the load and the fulcrum. Effort and resistance move in the same direction. Fishing rod, tweezer, and tongs are examples of class 3 levers.

Pulley

A pulley is a grooved wheel that turns around and axle which is held in place by mounting bracket.

Inclined Plane

An inclined plane is a plane tilted at an angle, with one end higher than the other.

Screw

A screw is actually a spiral inclined plane. It is composed of a cylindrical body with a spiral ridge called thread. The treads surround the cylinder from the tip to the head. A screw increases the force but a longer distance.

Wheel and Axle

The wheel and axle is a machine that has a small disk or shaft called an axle that is attached to a wheel.

Wedge

A wedge is an inclined plane or two inclined planes that meet each other to form a sharp edge.