What is the electric force between a +2 µc point charge and a –2 µc point charge if they are separated by a distance of 5.0 cm? show your work. (µc = 1.0 × 10–6 c)

The electrostatic force between two point charges is given by:

where
is the Coulomb's constant
q1 and q2 are the two charges
r is the distance between them

In our problem, charge 1 is

while charge 2 is

and their distance is
r=5.0 cm=0.05 m

So, the electrostatic force between them is


And the negative sign means the force is attractive, because the two charges have opposite sign.