Statics

In the previous examples, unbalanced forces produced acceleration, according to Newton's Second Law. One can also treat situations in which the forces are balanced and produce no acceleration. This arrangement is termed translational equilibrium. The study of these phenomena is called statics. In these problems there is no motion, so one can apply Newton's First Law and use the equations

$\sum$_i=1,..,n

_i = 0.

Statics is an important part of mechanical engineering. For example, to calculate what type and thicknesses of materials to use for bridges and skyscrapers, the statics engineer needs to employ the principles discussed here.

For a complete discussion of statics, it is also necessary to use the concept of rotational equilibrium, which will be introduced in a later chapter, once we have completed our discussion of circular motion and rotation.

However, it is already possible to investigate some interesting physical scenarios with only the concept of static translational equilibrium at hand. The following example and some of the homework problems in this chapter will further illustrate these concepts, and they will show that one can perform very interesting calculations by only relying on Newton's first law.