Principle of superposition:

forces between multiple charges

 

In a system where more than two point charges are there, coulomb’s law do not perform well. In that scenario the net electrostatic force acting on any charged particle due to a number of other charged particles is equal to the vector sum of all forces acting on that particle on a particular moment.

 

The individual forces are unaffected by the presence of other charged particle. This is called the principle of superposition.

 

 

Suppose q0 is the charge & we have to calculate the electrostatic force acting on it. r0  is the position vector of q0.

 

 

Suppose other charges are q1, q2, q3,  q4, ..………….. qn. Again

r1, r2, r3, r4 ………………….. rn are the position vectors of

q1, q2, q3,  q4, ..………….. qn respectively.

 



 

Now according to superposition of electrostatic forces, the net force acting on the charge q0 is








Where






 





Now from the vector form of Coulomb’s law is

 


Or







Similarly

















Therefore from (1)