When a rigid object is rotating about a fixed axis, every point on
the object rotates through the same angle in a given time and each point
follows a circular path at some perpendicular distance, r, from the axis.
Since all points turn through equal angles in equal times, all points on
the object have the same angular velocity. The relationship between
the magnitude of the velocity, v, of a point on the object and the angular
velocity, w, of the rotation is
v = r*w
Where r is the perpendicular disrance from the axis of rotation to the
point being considered.
In Andes problems all axes of rotation are perpendicular to the x-y
plane or in the z direction.