The Principle of Superposition for Coulomb’s Law of Electric Force | Doc Physics

electric forces follow the same laws as well bullies actually and so if Isaac Newton is sitting right here and there’s a big mean guy who comes up there will be a force on Isaac Newton away from the big mean guy which will probably be this direction and will probably be given by let’s put the bully right there so it’s exactly a way it will be given by the force from the bully is K C times the quantity of charge on one maybe that’s the bully’s charge times the quantity of charge on to that’s got to be Newton’s charge divided by how far apart he is from bully score and that’s going to be the direction of the force but the magnitude will be given by this the direction of force is directly away because as Newton gets picked on by bullies but if another bully comes up over here uh-oh and it’s the same distance away I mean he the bully is the same distance away from Isaac Newton as this bully is then you’ll have another force this direction and those forces seem like they’re going to be equal and opposite because we’ve set it up so that Isaac Newton is equally repelled from both those bullies so Newton has a choice clearly he could run this way or he could run this way but he’s not able to choose because they’re exactly here and he knows if he goes this way they’ll converge on him here he throws that way they’ll converging on here so right now Isaac Newton is actually paralyzed with fear another way to put that is that he’s in equilibrium because there’s no net force on him but what if we have two bullies over here and one over here now he’s got one force that’s up and to the left this force comes from this bully he’s got one force that’s down into the right that’s from this bully right here that’s this force right here and then he’s got this force that forces him that direction so by the principle of superposition because this force and this force that is this force and this force cancel exactly this force is the only force it’s going to be left on him so principle of superposition says super position says that you will have a net force only after you’ve added up all these forces as vectors consider the direction and you could go through the gory detail if you want but just think about running away from bullies