Editing Net force (section)

==Concept==

In physics, a force is considered a [[Euclidean vector|vector]] quantity. This means that it not only has a size (or magnitude) but also a direction in which it acts. We typically represent force with the symbol '''F''' in boldface, or sometimes, we place an arrow over the symbol to indicate its vector nature, like this: <math>\mathbf F</math>.

When we need to visually represent a force, we draw a line segment. This segment starts at a point ''A'', where the force is applied, and ends at another point ''B''. This line not only gives us the direction of the force (from ''A'' to ''B'') but also its magnitude: the longer the line, the stronger the force.

One of the essential concepts in physics is that forces can be added together, which is the basis of vector addition. This concept has been central to physics since the times of Galileo and Newton, forming the cornerstone of [[Vector calculus]], which came into its own in the late 1800s and early 1900s.<ref>Michael J. Crowe (1967). ''A History of Vector Analysis : The Evolution of the Idea of a Vectorial System''. Dover Publications (reprint edition; {{ISBN|0-486-67910-1}}).</ref>

[[File:Addition af vektorer.png|alt=Vector A going from coordinates (0, 0) to (3, 3), vector B going from coordinates (3, 3) to (5, 2) and their sum, A+B, going from coordinates (0, 0) to (5, 2)|frame|Addition of forces. '''Note:''' This picture uses a and b as variables for the vectors which is more common in math focused vector addition. In physics we use F to represent a force so rather than <math>\mathbf F_t =\bold\mathbf{a} + \bold\mathbf{b}</math> you would write it as <math>\mathbf {F_t} = \mathbf{F_1} + \mathbf{F_2}</math>.]]
The picture to the right shows how to add two forces using the "tip-to-tail" method. This method involves drawing forces <math> \bold\mathbf{a}</math>, and <math>\bold\mathbf{b} </math> from the tip of the first force. The resulting force, or "total" force, <math>\mathbf F_t =\bold\mathbf{a} + \bold\mathbf{b}</math>, is then drawn from the start of the first force (the tail) to the end of the second force (the tip). Grasping this concept is fundamental to understanding how forces interact and combine to influence the motion and equilibrium of objects. 

When forces are applied to an extended body (a body that's not a single point), they can be applied at different points. Such forces are called 'bound vectors'. It's important to remember that to add these forces together, they need to be considered at the same point.

The concept of "net force" comes into play when you look at the total effect of all of these forces on the body. However, the net force alone may not necessarily preserve the motion of the body. This is because, besides the net force, the 'torque' or rotational effect associated with these forces also matters. The net force must be applied at the right point, and with the right associated torque, to replicate the effect of the original forces.

When the net force and the appropriate torque are applied at a single point, they together constitute what is known as the [[resultant force]]. This resultant force-and-torque combination will have the same effect on the body as all the original forces and their associated torques.