Net Force Exerted by Two Charges on a Third Charge (Coulomb's Law)

[PHYSteve]

This problem has been posted before with different values for each variable and I
did as best I could to complete it similarly. However, when I attempt to input my final
answer I get it wrong every time. I just wanted to see where I am going wrong, thanks.

Homework Statement

Coulomb's law for the magnitude of the force F between two particles with charges
Q and Q' separated by a distance d is:

|F| = K(|QQ'|)/d²

Consider two point charges located on the x axis:
one charge, q₁ = -14.5nC, is located at x₁ = -1.745m
the second charge, q₂ = 36.5nC, is located at the origin.

What is the net force exerted by these two charges on a third charge
q₃ = 45.5nC, placed between q₁ and q₂ at x₃ = -1.085?

Your answer may be positive or negative, depending on the direction of the force

Homework Equations

K = 1/4\pi\epsilon₀

The Attempt at a Solution

I found the distance between q₁ and q₁ to be 0.660m
I found the distance between q₃ and q₂ to be 1.085m

I began by finding the charge q₁ exerts on q₃
by:

|F₁| = K*[|(-14.5*45.5)|/(0.660²)] = 1.362E¹³

(At this point in the problem there is a hint section asking for this force, when I submit the answer I calculated I am told it is wrong.)

And then I found the charge q₂ exerts on q₃ by:

|F₂| = K*[|(45.5*36.5)|/(1.085²)] = 1.268E¹³

(Again, there is a hint section asking for this value, which also tells me it is wrong)

From those two calculated forces I take F1 - F2 to get a final answer, which is ultimately deemed incorrect.

Any help would be appreciated!

 

[haruspex]

Units! The charges are quoted in nC, not C.

 

[PHYSteve]

Gah! I knew it would be something small. It always is. Thanks!