Which type of gears interacts with a grooved rack?

The correct answer is that rack and pinion gears interact with a grooved rack. In a rack and pinion system, the pinion is a small gear that engages with the linear, flat surface known as the rack. The grooved rack acts like a toothed track, and as the pinion turns, it rolls along the teeth of the rack, converting rotational motion into linear motion. This mechanism is commonly used in applications where precision linear movement is required, such as in steering systems for vehicles or in slide mechanisms.

This interaction is essential to the function of rack and pinion systems, as it allows the rotational energy from the pinion to translate into straight-line motion along the rack. Other gear types, such as helical, planetary, and bevel gears, do not operate with a linear rack and instead engage with other types of gears or surfaces to transfer motion or power. Understanding these distinct operations helps clarify why rack and pinion gears are uniquely suited to interact with a grooved rack.