Which simple machine operates around a fixed point known as a fulcrum?

The lever is a type of simple machine that consists of a rigid bar that rotates around a fixed point called a fulcrum. The lever is used to amplify force or change the direction of an applied force. When a force is applied on one end of the lever, it creates a moment around the fulcrum, allowing a heavier load to be lifted with less effort on the opposite end. This principle is utilized in various tools and devices, such as seesaws, crowbars, and scissors.

In contrast, a wheel operates on a different principle, as it rotates around an axle rather than a fulcrum. A pulley also helps change the direction of a force but involves a wheel and a rope system rather than a single bar pivoting around a point. The screw, while a simple machine as well, functions by converting rotational motion into linear motion and does not operate around a fulcrum. Thus, the lever distinctly embodies the fundamental characteristics of a simple machine that utilizes a fulcrum for operation.