# What Is a Tool? What are Simple Machines?

(Last Updated On: April 29, 2019)

## What Is a Tool?

It’s a simple question that tends to elicit many different responses: what is a tool?

We all have a pretty basic idea of what a tool is and what makes it a tool. You probably thought of a hammer, screwdriver, pliers, or even a knife when you first saw this post. Of course, you’d be right.

The definition of a tool is actually pretty broad in most dictionaries. Merriam-Webster, for example, describes a tool as “a handheld device that aids in accomplishing a task.” Most other tool definitions are also along those lines. And it’s because of that general definition that many often apply the term tool loosely to any thing that is a means to an end. This often leads to fun debates about whether or not certain objects are in fact tools or not (in much the same way people argue about what is a sandwich?)

What we can be certain of is that all the objects mentioned earlier are tools. But they also have something else in common. They all have their basis in simple machines.

## What Is a Simple Machine?

At a base level, simple machines are all about the redistribution of force to do work. If you remember your physics, work is equal to force times distance (W = Fd), ergo, the greater distance you’ve applied a force, the more work you’ve done. Force also equals mass times acceleration (F = ma), so we guess you could say W = mad, which is how you might feel about physics. That also means if you apply a lot of force to push a boulder up a mountain, only to have it push you back to where you started, you have done zero work. Sorry Sisyphus.

So back to redistributing force. Simple machines change the amount of force required to do the same amount of work. It’s probably best to visualize this with one of the most basic simple machines; the inclined plane.

If you want to say, go up 3 feet, you could jump up 3 feet and get there right away. You’d travel exactly 3 feet, and exert a (relatively) lot of force in the process. But say you don’t want to exert the force that’s required to jump 3 feet. So you get a ramp (the inclined plane) and set it up. You’ll be able to walk comfortably up that ramp to go up that height. You’ve done the same amount of work, but have exerted less force (and perhaps less effort) in the process.

## How Are Our Handheld Devices Simple Machines?

Here’s a list of the simple machines:

• Levers
• Wheels & Axles (exploits torque on wheel to spin axle)
• Inclined planes
• Screws
• Pulleys
• Wedges (technically modified inclined planes, so some people will lump these with them)

If you think about it, a lot of tools in the traditional sense can be boiled down to one of the six simple machines. Let’s look at knives. Knives are by definition wedges. Either side of the edge is just an inclined plane, and you apply force to the top of the knife to split something.

Think about cutting a vegetable. The force you’re applying to the top of the knife is being redistributed to a sideways force, perpendicular to the one you’re applying. So the wedge (simple machine) is making it easier for you to split your vegetables because now you don’t have to rip them apart. You just have to apply a downwards force.

While we can all debate about which objects count as tools and which don’t, what is clear is that tools make performing daily tasks easier.

Now that you know a thing or two about tools, test your skills in the quiz below!