here force between two particles is given by Coulomb's law where two particles will either repel or attract each other
this force of attraction or repulsion is given by the equation
[tex]F = \frac{kq_1 q_2}{r^2}[/tex]
here we know that
[tex]q_1 , q_2[/tex] = two point charges
r = distance between two charges
so now we will substitute all values in it
[tex]F = \frac{kq_0q_1}{d_1^2}[/tex]
so above is the force between two point charges