Which axis describes rotational movement around the z axis?

The correct choice for describing rotational movement around the z axis is associated with the c axis. In a three-dimensional coordinate system, the axes are generally defined as follows: the x axis runs horizontally, the y axis runs vertically, and the z axis extends outwards perpendicularly to the x and y axes.

When discussing machine tools and operations such as lathes or CNC (Computer Numerical Control) machines, the c axis specifically refers to rotation around the z axis. This is crucial for operations that involve angular movement, allowing the workpiece to spin or rotate while machining along the z axis. Therefore, the c axis effectively represents and enables the rotational movement necessary for various manufacturing operations that require precision and control around the z axis.

In contrast, the x and y axes represent linear movements along their respective dimensions, and are not associated with rotation. These axes focus on translational, not rotational, motion. Hence, they would not correctly describe movement around the z axis.