What role do gears play in mechanical systems?

Gears are essential components in mechanical systems primarily because they convert rotational motion. When one gear turns, it transfers its motion to another gear, effectively impacting the speed and torque of the resultant motion. This transmission is critical in applications where precise control of rotation is required, such as in vehicles, machinery, and various tools. By changing the size of the gears, systems can enhance or reduce rotation speed, which in turn affects the force applied to an object. This ability to modify the characteristics of motion makes gears fundamental in achieving desired performance in a wide range of mechanical applications.