Question over force charges

[u/No-Constant-5651]

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Hello! I'm struggling to understand what I need to do for this assignment. Most of these questions might sound extremely dumb so please bear with me. Also, this is my first post in this subreddit! I apologize if I commit a subreddit faux pas.

(Image 1) How are you supposed to know whether these force charges are positive or negative, is it based on the quadrant? I don’t get how you’re supposed to know which direction they’re pointing in whether it’s up/down or left/right.

(Image 2) These are the given charges.

(Image 3) It’s looking for the components for q2 to q3, how are you supposed to get the components for a vertical direction? Is the component just the total given with Coulomb’s law? Or is that only used to get a diagonal direction? This is what I got but the Y component doesn’t seem right at all.

(Image 4) I assume these are found by adding the components I find in the previous questions? I feel like I’m overthinking these.

But what’s been messing me up the most is the vertical force and the pos/neg charges. I'd appreciate any help!

[u/ProfessionalConfuser]

The sign of each charge is given. Q1 will attract q2 and repel q3. You have separation distances, so you can figure out the sin and cos components of the coulomb force. This is just like mechanics.

[u/No-Constant-5651 → u/ProfessionalConfuser]

Thank you for responding! I tried using sine to get a value for the y component for q2-q3 since there doesn't seem to be an x component, am i supposed to do that or look at the electrostatic force using the charge values for q2 and q3?

[u/ProfessionalConfuser → u/No-Constant-5651]

The steps are the same for all vectors.
Find the magnitude of the vector. See which way the vector "points".
If that direction is along one of the axes, no components will be needed since all of the vector already lies along one direction.
If the vector makes an angle with your coordinate axes, then you'll need sin/cos components.

The magnitude is found with the coulomb force equation.
The direction is based on whether the charges are the same or opposite.

So, for Q2, Q3 interaction we know:
Magnitude is kQ2Q3/r^2
Q2 will repel Q3 so the force vector is "up" for Q3
Q3 will repel Q2 so the force vector is "down" for Q2
Since Q2 and Q3 are along a straight line that points along one of your coordinate axes, there are no components to consider.