Question

What is the force, in terms of Coulomb's constant, between two electrical charges of `2` `C` and `-14` `C` that are `15` `m` apart?

Answer 1

The force between two charged particles a distance `r` `m` apart is given by `F=(kq_1q_2)/r^2` where `k` is Coulomb's constant. The answer is `F=(k*2*(-14))/15^2 = (-28k)/15^2 =(-28k)/225`

Explanation:

I'm not sure I can add much more explanation on this one. We were asked for an answer 'in terms of Coulomb's constant', so we've left `k` as `k` rather than substitute in its value of `9.0xx10^9 Nm^2C^-2`.

The negative sign of the answer just means the two objects experience a force attracting them to each other, because they have opposite charges, rather than a force repelling them, as they would if their charges were the same.