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.

 

[HalfLostAndSearching]

I can confirm that your calculation is correct. The electrostatic force between two point charges is given by Coulomb's Law, which states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. In this case, the distance is 3 meters and the charge is 3 microCoulombs, which results in a relatively large force of 89.9 kiloNewtons. This may seem like a large force, but it is important to remember that the electrostatic force is one of the fundamental forces of nature and can be quite strong, especially when dealing with large charges. Additionally, the force may seem large in comparison to everyday objects, but on an atomic or molecular scale, it may be relatively small. Overall, your calculation is correct and there is no need to be concerned about the magnitude of the force.