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Lever an Obelisk

Perhaps you don't think too much about using "The Advantage," but there's no way you can live through a day without utilizing it in some way. No, we're not talking about a type of computer, or a brand of clothing, or even a credit card. We're talking about mechanical advantage—more specifically, about one of the most basic of all machines that makes use of mechanical advantage: the lever.

Arm diagram Levers are everywhere. The light switch on the wall, for example, and the stapler on your desk. You use levers when you shift gears on a bike and when you hit the brakes. A doorknob is a type of lever. And then there's your body. Your body contains many, many levers—wherever there's a movable joint there's a lever.

This activity is about the lever as a basic tool. The ancient Egyptians used levers in building the pyramids. Although it is not known exactly how they erected the great obelisks, it's a pretty sure bet that they used levers in some way.

Diagram of levering up an obelisk In the following activity you're asked to lift one end of a relatively small obelisk three feet. You have a lever, a movable fulcrum, weights, and supporting stones at your disposal. Your goal is to lift the obelisk using as few of the weights and support stones as possible.

Good luck.

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