PHYSICS
posted by ELIZA .
A thundercloud has an electric charge of 43.2 C near the top of the cloud and 38.7 C near the bottom of the cloud. The magnitude of the electric force between these two charges is 3.95 x 106 N. What is the average separation between these charges?
I'm confused, help pleeease? :)

Use Coulombs law
force=kQtop*Qbottom/d^2 solve for d 
I used the formula, but I still don't know how to solve the problem ? Did you get it ?

Did anyone get the answer for this?

You have to convert km to m