How to Calculate the Magnitude and Angle of the Total Force of Three Charges?

[Mary O'Donovzn]

How do you calculate compute the the magnitude of the total force of three charges and also the angle it makes with the x-axis? Knowing the magnitude and also the 2d co ordinates of the charges.

I have deliberately not given any specific values because this is not homework its a question from old exam paper and I want to know how to do it because I have a gut feeling it will be on the mid term and I honestly don't know what to do so if somebody could give me a step by step that would be great!

The only thing I know for definite I use the below formula but that's the only a clue I got from my tutor but I don't know how to use it I don't even know where to start I have no examples or anything.

K0 * Q1.Q2 / d^2 * r hat Thanks :)

 

[Doc Al]

I assume you need to find the total force on one of the charge due to the others? Just find the force exerted by each charge separately. (Coulomb's law will tell you that.) Then add up the force vectors to find the total.

FYI: Even though it's not strictly homework, problems like this (or textbook, exam, coursework, homework type problems in general) do belong in the HW section.

 

[Simon Bridge]

Do you know how to work out the magnitude and direction of the force on one charge due to only one other charge?

 

[Hawzel Abel]

it is easy to understanding，but to me it is difficult to display in English。

 

[Hawzel Abel]

Do you want to calculate the force of one charge by the other two charge, the magnitude of the two forces are directly related to the vector sum.

 

[jtbell]

Have you studied how to add vectors?

 

[Brian_H]

As I see it, you must need to study about Vector. Vector is very important in Physics as well as Mathmatics

 

[Mary O'Donovzn]

One I find the force F12, F13 and F23 do I add them all up?
I don't know how to work out the magnitude of a unit vector which seems to be called R hat? Like its something to do with cosi + sinj
Do Vector components come into this at any point and if so how are they calculated?

 

[Doc Al]

One I find the force F12, F13 and F23 do I add them all up?

That depends on exactly what you are asked to find. Can you post the complete question, word for word as it was given?

I don't know how to work out the magnitude of a unit vector which seems to be called R hat?

The magnitude of a unit vector is 1. (That's why it's called a unit vector.) Its purpose is to indicate direction.

Do Vector components come into this at any point and if so how are they calculated?

You'll undoubtedly need to add vectors together. Finding and adding their components is one way to do it. Read up on vectors here: Basic Vector Operations

 

[Mary O'Donovzn]

The question I posted is the full question like I just took out the values which were in brackets. Is it unsolvable?

So with regards to the unit vector do I just but the distance it is over one and get r hat? I don't use cos θ or sinθ?

okay thank you I will look at the link

 

[Doc Al]

The question I posted is the full question like I just took out the values which were in brackets. Is it unsolvable?

It's still a bit unclear to me.

How do you calculate compute the the magnitude of the total force of three charges

How many charges are there? The total force of the three charges on what? Is there a diagram to go along with it?