Question

A charge of `3 C` is at `(4 ,-7 )` and a charge of `-1 C` is at `(-2 , 3 )`. If both coordinates are in meters, what is the force between the charges?

Answer 1

net displacement between the two charges is `r=sqrt((4-(-2))^2 + (-7-3)^2)=sqrt(136) m`

So, the electrostatic force acting between them will be `9*10^9*3*(-1)/136=-1.97*10^8N` (using, `F=(kq_1 q_2) /r^2`)