The 6 Simple Machines
A pulley is a wheel on an axle. They are usually designed to change the direction while lifting loads or applying other forces. The different types of pulleys include fixed, moveable and compound pulley systems. Some examples of pulleys are: elevators, cargo lifts, wells, and in construction sites to lift objects.
Levers are simple machines that consist of a beam or a rod on a fixed hinge or fulcrum. The word is originated from France, the word "lever" means to raise in the french language. They are usually used to lift heavy objects and make them move quicker. Levers are used in wheelbarrows, seesaws, and in door handles.
Wheel and Axle
A wheel and axle is a wheel attached to an axle so the two parts can move together to complete a task. Both the wheel and axle rotate simultaneously on an axis. Although the parts should move together, this type of machine is sometimes used where the wheel doesn't rotate with the axle. Some real life examples of a wheel and axle are: car tires, steering wheels, screwdrivers, and door knobs.
An inclined plane is a flat surface that is tilted at an angle so that one end is higher than the other. These machines are often used to move heavy objects or vertical obstacles. Ramps are inclined planes and they are usually used to get people or objects off of the ground and to a higher distance, Rolling a truck tire up an inclined plane requires less force and is easier than lifting it straight up. Inclined planes are used everywhere, some examples are: ramps, driveways, slides and pyramids.
The screw is a machine that convert rotational motion to linear motion. It also turns torqu (rotational force) into linear force. A screw is a cylinder like object that contains grooves along the outside of it which are also called threads. This mechanism can go through another object that has a threaded hole in it or a nut could rotate onto it. Screws are used in bottle caps, nuts and bolts, jar lids and screws.
A wedge is a triangular shaped machine that can seperate two objects, seperate parts of one object, hold an object in place and/or lift an object. Shorter wedges that have wider angles would be able to do the task faster but that requires more work than a long wedge with a narrow angle. Wedge examples that we see everyday are: kinves, axes, doorstops and chisels.