Mechanics: Introduction

 Mechanics is the state of rest or motion or motion of bodies subject to forces. 

This is split into rigid-body mechanics, deformable body mechanics, and fluid mechanics. Statics is the equilibrium when an object is in constant motion and acceleration. Dynamics is the accelerated motion of bodies that are moving.

The distance in space is measured by the unit length. 

A particle is an element of insignificant size that can be neglected. A rigid body is a bunch of fixed distance particles that can be neglected. A concentrated force is the effect of loading, which is supposed to have an effect on the body. An example of this force is the force between the wheel and the ground.