Electrical force between charges

[Latsabb]

edit: I see that my title is incorrect. This isn't between charges, it is between a charge and a point, sorry about that.

The problem:
Find the magnitude of the electrostatic force that works on a point 3 meters from q1.

q1=3μC

My attempts:
Feq1=1/(4πε₀)*(q1/r)
r=3m
1/(4πε₀)=8.988x10⁹

Feq1=8.988x10⁹*(3x10^-6/3)=89.9kN

As far as I can tell, this is the way it should be done, but the force seems pretty large... Is there something that I am missing? Or is this actually correct?

 

[SteamKing]

edit: I see that my title is incorrect. This isn't between charges, it is between a charge and a point, sorry about that.

The problem:
Find the magnitude of the electrostatic force that works on a point 3 meters from q1.

q1=3μC

My attempts:
Feq1=1/(4πε₀)*(q1/r)
r=3m
1/(4πε₀)=8.988x10⁹

Feq1=8.988x10⁹*(3x10^-6/3)=89.9kN

As far as I can tell, this is the way it should be done, but the force seems pretty large... Is there something that I am missing? Or is this actually correct?

Well, you can start by checking the units in your calculation, in particular Coulomb's constant. Are your formula and calculation dimensionally correct?

 

[Latsabb]

Coulombs constant is N·m²/C², while q1/r would be C/m. So put together that would give me N*m/c... That means that there should be a C²/m², which I know to be q0*q1/r² but that is between two charges, not the force at a point.

I guess that means that Feq1=1/(4πε0)*(q1/r) isn't an actual equation? Which leaves me confused, because that is what was given to me in someone's notes...

 

[Latsabb]

I spoke with the person I got the notes from, and it should have been r² in the denominator, which would give me N/C, or the field strength. Thank you for your help.