# Size, direction and potential

1. Mar 25, 2014

### besnik93

1. The problem statement, all variables and given/known data
Three ions, each with a charge Q = e, located at the corners of an equilateral triangle with
side length r midpoint of one of the sides of the triangle described M.

a) Calculate the magnitude and direction of the electric field E of the three ions generated at point M.
Size E is expressed by the symbols e and r addition, the value of E is calculated when
r=1,2*10-10m

b) Calculate the electric potential V at point M. Size V must be expressed by the symbols e and r
In addition, the value of V is calculated as r=1,2*10-10m.

3. The attempt at a solution

a) I know that the electric field is a vector which is the vector sum of all the sources contribution, but I find it hard to express it.
b) I know that the potential is a scalar size (ie without direction) whose value is the sum of all sources contributions.

2. Mar 26, 2014

### dauto

Calculate the field due to each individual ion (can you do that?) and add the vectors. do the same for the potential which is easier since at the end you have a scalar addition.

3. Mar 26, 2014

### besnik93

I dont know how to add the vectors?

4. Mar 26, 2014

### dauto

Than you have to go back to basics, practice vector addition, before attempting that problem.

5. Mar 26, 2014

### besnik93

How can it become vectors, i dont understand it

6. Mar 26, 2014

### dauto

And I don't understand your question. What is that "it" you're talking about? nothing becomes vectors. The electric field IS always a vector and the potential is never a vector.