Particle and Fluid Motions in Gravitational and Electromagnetic Fields

Abstract

In Chapter 2, we presented the kinetic and the fluid descriptions of an N-particle system. We can recover the familiar single particle equations by ignoring the many body effects like collisions and stresses and the extensive quantities like pressure and temperature. For an important class of problems, the knowledge of the motion of a single particle under the action of various forces provides us with great insight at a modest effort. Under certain circumstances, the entire fluid does what each particle does. We shall study these drifts which are common to both a single particle as well as a fluid. But there are additional drifts which originate entirely due to the fluid properties such as pressure forces. The two types of drifts in the presence of space and time dependent fields will be studied in this chapter.