What are the equations and solution for electrostatics?

[asi123]

Homework Statement

Hey guys.
Is it correct what I did there?

Thanks in advance.

Homework Equations

The Attempt at a Solution

 

[Hootenanny]

Homework Statement

Hey guys.
Is it correct what I did there?

Thanks in advance.

You should be able to tell without any calculation that your solution is incorrect.

HINT:

Spoiler

Check the sign

 

[asi123]

You should be able to tell without any calculation that your solution is incorrect.

HINT:

Spoiler

Check the sign

Yeah, but what about the magnitude?
As for the sign, it should be opposite from q, right?

Thanks.

 

[Hootenanny]

Yeah, but what about the magnitude?
As for the sign, it should be opposite from q, right?

Thanks.

Looks okay to me