ES30 Vector Resolution, Two Points on a Line 
Frequently a force vector is defined by two points in space through which the force passes. 
where and 
The unit vector which defines the line passing through the two points is given by: 

The force and its components can be determined... 
As an example, consider a cable (AB) with a force of 320N, where the x, y and z components of the force at A are to be found. 
The components of the distance may be set proportional to the components of the force. 
The figure shows this representation graphically. 
and 
The forces, therefore, are as shown. 
The components of distance, moving from A to B are... 
This yields ... 
Substituting into the equation shown previously, yields... 
Solving... 