# Simple Machines

## Pulley

A pulley is a simple machine that uses grooved wheels and rope to raise, lower or move a load. A pulley can be used to make lifting heavier things easy. Some everyday examples of a pulley are: marine pulley, flagpole pulley, clothesline pulley, rock climber pulleys, and a steam shovels

## Lever

A lever is a stiff bar that rests on a support called a fulcrum which lifts or makes loads. Levers are used to lift heavy objects. Some everyday examples of a lever are: baseball bat, hoe, clippers, stapler,and can opener.

## Wedge

A wedge is a triangular shaped tool, and is a portable inclined plane, and one of the six classical simple machines. It can be used to separate two objects or portions of an object, lift up 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. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width.[1][2] Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle. Some everyday examples of a wedge are: ax, rake, fork, chisels, car tire wedge.

## Wheel and Axle

The wheel and axle is one of six simple machines identified by Renaissance scientists drawing from Greek texts on technology. The wheel and axle is generally considered to be a wheel attached to an axle so that these two parts rotate together in which a force is transferred from one to the other. A wheel and axle is used for basic machine component for amplifying force. In its earliest form it was probably used for raising weights or water buckets from wells. Some everyday examples of a wheel and axle are: pencil sharpener, roller skates, record player, door knobs, bicycle.

## Inclined Plane

An inclined plane is a flat supporting surface tilted at an angle, with one end higher than the other, used as an aid for raising or lowering a load. Some everyday examples of an inclined plane are: roller coaster, parking ramp, stairs, ladders, hill with cable car.

## Screw

A screw is a simple machine made up of another simple machines. It is an inclined plane wrapped around a cylinder. The most common uses of screws are to hold objects together and to position objects. Some everyday examples of a screw are: light bulb, meat grinder, drills, machine screws, door lock.