ABSTRACT
In this chapter we review various topics and concepts about inertia. Many readers will be familiar with a majority of these topics; however, some topics, particularly those concerned with three-dimensional aspects of inertia, may not be as well understood, yet these topics will be of most use to us in our continuing discussion of mechanical system dynamics. In a sense, we have already begun our review with our discussion of mass centers in the previous chapter. At the end of the chapter, however, we discovered that we need additional information to adequately describe the inertia torque of Eq. (6.9.11), shown again here:
(7.1.1)
Indeed, the principal motivation for our review of inertia is to obtain simplified expressions for this torque. Our review will parallel the development in Reference 7.4 with a basis found in References 7.1 to 7.3. We begin with a discussion about second-moment vectors — a topic that will probably be unfamiliar to most readers. As we shall see, though, second-moment vectors provide a basis for the development of the more familiar topics, particularly moments and products of inertia.
