Force Vector along a Line

Quite often in three-dimensional statics problems, the direction of a force is specified by two points through which its line of action passes. Consider a three-dimensional static pole with a cable anchored to the ground.

Consider a three-dimensional static example like a pole with a cable anchored to the ground. Here, a tension force is acting along the cable.

Now, consider a Cartesian coordinate system with an arbitrary origin to represent the force as a Cartesian vector.

P_A and P_B represent the position vec...