When the mass of an object is distributed over some dimensions, it will possess a moment
with respect to any axis of choice. Figure 10-1 shows a mass of general shape in
an xyz axis system. A differential element of mass is also shown. The mass moment
(first moment of mass) of the differential element is equal to the product of its mass
and its distance from the axis of interest. With respect to the x, y, and z axes these are;