Calculating Electric Force Between Balloon & Denim

[Dumb4Physz]

Homework Statement

A balloon rubbed against denim gains a
charge of −2.0 μC.
The Coulomb constant is 8.98755 ×
109 N · m2/C2.
What is the electric force between the bal-
loon and the denim when the two are sepa-
rated by a distance of 6.0 cm? (Assume that
the charges are located at a point.)
Answer in units of N.

Homework Equations

q=n.e
Fe=kq1q2/r^2
e=Fe/q

The Attempt at a Solution

i tried plugging everything in but they were wrong when i checked them. please explain to me what i did wrong! thanks .

 

[rl.bhat]

Show your calculations. With out that it is not possible to say what you did wrong.