What is the force, in terms of Coulomb's constant, between two electrical charges of #-2 C# and #2 C# that are #3 m # apart?

1 Answer
Jun 18, 2016

#F=-4/9K#.

Explanation:

The Coulomb's force is given by

#F=K(Q_1Q_2)/r^2#

where #K# is the Coulomb's constant, #Q# are the charges and #r# the distance.

With your numbers we have

#F=K(-2*2)/3^2=-4/9K#.

Because you ask to keep it in units of the Coulomb constant, I will not continue the calculation evaluating #K#.
The negative sign tell us that the force is attractive because the two charges have opposite sign.