Statics of a Particle

Abstract

If the surroundings act on a system in such a way as to tend to change the motion of the system then we say that a force exists. The force is the action of the surroundings, but nevertheless it is usual to state that the force itself is acting on the system. The forces encountered in practice are usually found to be applied to the system as a whole or over finite areas of the system boundary. Initially, however, we consider only the forces acting on a single particle. Any one such force can immediately be characterised by its magnitude and its direction, and in addition, for a single particle, by its line of action, since this passes through the particle. In the next chapter we extend the discussion to particular assemblies of particles, namely rigid bodies.