Chapter 9
Motion Under Central Forces
Central forces enjoy a special place in physics. The most prominent forces in nature, namely, the force of gravitation between two spherically symmtric massive bodies (e.g., a star and its planet) and the electrostatic force (Coulomb force) between two point charges in slow motion 1 are central forces.
By the term “central force” we mean a force F(r) acting on a particle P which is (a) always along the line CP joining P to some centre C (Fig. 9.1a), and which is (b) a function only of the radial distance r measured fron the centre C. The function F(r) is independent of the angle θ that the radius vector r makes with some arbitray direction in space.
FIGURE 9.1 Examples of a central force: (a) A schematic ...
Get Mechanics now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
