In this second chapter we continue to work with the Energy-Interaction Model. We add all kinds of mechanical interactions to the thermal interactions we treated in Chapter 1. The term “mechanical” is ...In this second chapter we continue to work with the Energy-Interaction Model. We add all kinds of mechanical interactions to the thermal interactions we treated in Chapter 1. The term “mechanical” is typically used to imply everything other than thermal. We introduce the Intro Spring-Mass Oscillator Model in this chapter as an application of the Energy-Interaction Model. The Spring-Mass Oscillator Model will also play an important role in Chapter 3 for the particle model of matter.