When you push or pull with a simple machine, you are applying a force and doing work. And, if you get more force out of a machine than you put into it, then that machine has a mechanical advantage.

imple machines help us change the amount of force or the direction of the force needed to move an object. Find out how by learning more about levers. Major Funding by the Laura Moore Cunningham ...

Hundreds of thousands of years before the invention of the wheel, some unlucky hominin stepped on a loose rock or unstable log and—just before they cracked their skull—discovered that a round object ...