Force and Pressure: Balanced Forces

Fundamental Nature of Forces

A force is a push or a pull on an object. Forces always appear in pairs, meaning one force acts in one direction while another equal reaction force acts in the opposite direction. For a stationary box placed on a table, the downward force of its weight $W$ is equal to the upward normal force $N$ exerted by the table. For instance, if the weight of the box is $50\,N$ and the normal force from the table is $50\,N$, the forces are in balance, resulting in no change in the position of the object.

Balanced Forces and Motion

When multiple forces act on an object and are balanced, they cancel each other out so that the object behaves as though no force acts on it at all. With balanced forces acting on an object, such as equal opposing forces of $300\,N$, the object does not change its state of rest or motion, remaining either stationary or continuing at a steady speed.