# Coulomb's Law and electric force

1. Feb 20, 2006

### angel_romano

I can't seem to figure out how to do this problem. I've tried the equation for coulomb's law, but I can't get the right answer. If somebody can just help me with setting the problem up.

Two objects ar rubbed against each other. Object B gains a charge of -5 nano-coulombs. What is the electric force between the two objects when the distance between them is 3.0 cm? Also, how do I convert the nano-coulombs to coulombs?

2. Feb 20, 2006

### nrqed

You multiply by $$10^{-9}$$, ($$1 nc= 10^{-9} C$$).

the question si very ambiguous. *Assuming* that the two objects were initially uncharged and *assuming* that they can be treated as point charges then the answer should be given by Coulomb's law. (what did you use for the two charges? One should be +5 nc and the other -5 nc. Also, did you put the distance in meters?)

Pat