Let’s say you needed to lift something very heavy. How could you do it? Sure, you could ask a friend to help – or maybe even two or three friends. But what if the object was REALLY heavy? You might need some extra power, right? Simple machines increase force and energy, allowing us to do jobs more quickly and efficiently.
Types of Simple Machines
Inclined plane: a type of ramp that allows you to push something gradually up, rather than lifting it. Think of a wheel chair ramp or even a road on a steep mountain. The wheel chair or car moves up gradually and safely.
Lever: A lever is a long, solid object, such as a piece of wood, with a fulcrum resting somewhere along it. A fulcrum pivots the solid object. A teeter totter is one example of a lever. The fulcrum is the base of the teeter totter. Two people sitting on either side make up the load.
Pulley: Think of an old-fashioned well with a rope strung through a wheel. At the end of the rope is a bucket of water. Rather than pulling the rope up to pull the bucket out of the well, you pull down on the rope as it hangs down from the wheel. Pulling down is easier than pulling up because the force of gravity helps you.
Screw: A screw is really an inclined plane that has been twisted. Screws are more effective at securing two pieces of wood together than nails because the grooves in the screws catch the wood, forming a secure connection. Faucets, jar lids, and even circular stairs are all forms of screws.
Wedge: A wedge is two inclined planes put together. Wedges are used to either tear or cut something apart or to secure two things together. An axe splits a log apart. A shovel divides dirt. An ice pick breaks ice. On the other hand, a thumb tack is a type of wedge used to keep papers together. A nail secures two pieces of wood.
Simple machines have been around for thousands of years. To learn more, visit Idaho Public Television.