In summary, the conversation discusses how to calculate the magnitude and angle of the total force on one charge due to the presence of two other charges. The formula K0 * Q1.Q2 / d^2 * r hat is mentioned, but the speaker is unsure how to use it. They mention needing to find the force exerted by each charge separately and then adding them together using vector addition. The concept of unit vectors and vector components is brought up, and it is recommended to do some research on vectors. The full question is unclear, as the number of charges and what the total force is acting on is not specified.
  • #1
Mary O'Donovzn
17
0
OP warned about not using the homework template
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 :)
 
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  • #2
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.
 
  • #3
Do you know how to work out the magnitude and direction of the force on one charge due to only one other charge?
 
  • #4
it is easy to understanding,but to me it is difficult to display in English。
 
  • #5
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.
 
Last edited by a moderator:
  • #6
Have you studied how to add vectors?
 
  • #7
As I see it, you must need to study about Vector. Vector is very important in Physics as well as Mathmatics
 
  • #8
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?
 
  • #9
Mary O'Donovzn said:
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?

Mary O'Donovzn said:
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.

Mary O'Donovzn said:
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
 
  • #10
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
 
  • #11
Mary O'Donovzn said:
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.

Mary O'Donovzn said:
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?
 

What is Coulomb's Law formula?

Coulomb's Law formula is an equation that describes the electrostatic force between two charged particles. It states that the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

How do I use Coulomb's Law formula?

To use Coulomb's Law formula, you need to know the charges of the two particles and the distance between them. Once you have these values, you can plug them into the equation and solve for the force.

What are the units for Coulomb's Law formula?

The units for Coulomb's Law formula are Newtons (N) for force, Coulombs (C) for charge, and meters (m) for distance. The equation can also be written in terms of electric field (N/C) and permittivity (C^2/Nm^2).

What is the significance of Coulomb's Law formula?

Coulomb's Law formula is significant because it helps us understand and predict the behavior of electrically charged particles. It is also a fundamental principle in electromagnetism and is used in many areas of science and technology, such as electronics and particle physics.

Are there any limitations to Coulomb's Law formula?

Yes, Coulomb's Law formula is only applicable to stationary charged particles and does not take into account the effects of relativity. It also assumes that the charges are point particles and does not account for the size or shape of the particles. Additionally, the formula breaks down at very small distances or when dealing with extremely large charges.

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