The Coulomb force between two charges is defined as: Fc=(k*Q₁*Q₂)/r² where k=9*10^9 N m² C⁻², Q₁ and Q₂ are charges and r is the distance between those charges.
In our case:
Q₁=2*10^-6 C
Q₂=4*10^-6 C
r=2 m
Now we simply plug in the numbers into the equation:
Fc={(9*10^9)*(2*10^-6)*(4*10^-6)}/2^2=0.018 N
The Coulombs force between the two positive charges is Fc=0.018 N and it is a repulsive force because both charges are positive.
