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Wooden model of an Egyptian man plowing with two oxen

Ancient Egyptian cattle plowing (Louvre Museum, Paris)

You might think you know what work is, like homework, or having to pick up your room, right? But to scientists, work has a more definite meaning: work is force x distance.

That means that you can measure work by measuring how much force, or energy, it took to move something, and multiplying that by how far you moved it (or how many of them you moved). It takes a certain amount of energy to push a plow through the fields. Then it takes more energy to push that plow up and down four furrows than it takes to push it down only one furrow.

Children working in a brick factory in what is now Pakistan

Children working in a brick factory in what is now Pakistan

In the same way, it takes a certain amount of energy to pick up one brick. And it takes twice as much energy to pick up two bricks. If you move two bricks one mile, you’ve done the same amount of work as moving one brick two miles.

To make work easier, people use machines like leverspulleyswedges, wheels, and inclined planes.

More about levers
More about pulleys
Or more about wedges
More about wheels

Bibliography and further reading about work:

Simple machines
Physics
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