Considering electrostatic force,a part of electromagnetic force,
When a positive point charge (fixed) and a free negative point charge are in surroundings,we observe an attraction between them. Also,the force of attraction is along the line joining the two charges.
Just for an imagination,
I thought that there can be forces ,not along the line joining the two charges, which can also contribute to attraction force. I also considered those forces to be symmetric. Seeing the net effect, it also created an attractive force in the direction of line joining both the charges.
This arose me a question, Is electrostatic force (similar for gravitational force too) between charges just a single force or a net force? How can we say a fundamental force is a net force or not?
This can also be rephrased as, Is electrostatic force between two charges is along the line joining the two charges or just we are perceiving so as a net force?
To explain electrostatic force we developed the idea of electric field and field lines. So, F=Eq. When we draw field lines around a positive charge, the density of lines gives us an idea of electric field intensity around the charge.
Electrostatic force is related to field intensity. Also, field intensity at a point is represented by density of field lines. Density depends on surroundings. This gives me an idea that, force at any point depends on surrounding (supporting my question , "is force just along the line joining the two charges?" ) , as field intensity depends on density, which needs the idea of surrounding region. I know the idea of density of lines related to field intensity is just from pictorically representing field lines. But I feel that this idea can support my question, but not sure.