ABSTRACT
This chapter introduces the concepts of energy and conservative forces. It also discusses how energy can be used to describe the motion of a system and introduces the concepts of equilibria stability. It begins by studying one-dimensional systems because they are easy to visualize, and then extends the concept of work and energy to two, and three-dimensional systems, including a discussion of line integrals. Using Newton’s second law leads to a second-order ODE that describes the particle’s motion. An alternative approach to solving physics problems involves the concept of energy. Energy is a scalar quantity, and therefore, simpler to work with. The concept of energy is particularly useful when so-called conservative forces are acting on a system. The potential energy of the interaction between a pair of neutral atoms or molecules is often described by the Lennard-Jones potential function. The chapter concludes with a discussion of the energy of multiparticle systems.
