# Electric field

1. Jan 19, 2009

### -EquinoX-

1. The problem statement, all variables and given/known data

Find the electric field at position (2.00, 0)

2. Relevant equations

3. The attempt at a solution

I am just confused by the question actually, does it mean at point 2 m to the right of 0,0? or is it to the left?

The way I would solve this problem is by finding the electric field that each charges made 2 m from the point, for example the -.4nC, we can find the electric field at 2.00 by ke * -.4nC/2.5^2, and as well for the others and sum them all together, am I right?

2. Jan 19, 2009

### LowlyPion

Yes. The way I read the diagram, the 5nC is at the origin and they are asking for the point 1.2 m to the right of the 3nC charge.

Yes. Superposition is right. The distances for each (left to right) to be clear would be 2.5, 2, 1.2 .

3. Jan 20, 2009

### -EquinoX-

so basically it's just ke * -.4nC/2.5^2 + ke * 5nC/2^2 + ke * 3nC/1.2^2

4. Jan 20, 2009

### LowlyPion

That's what it looks like to me.

5. Jan 20, 2009

### -EquinoX-

What if the question now is (0, 2.00) instead of (2.00,0)?

6. Jan 20, 2009

### LowlyPion

That would mean apparently it was on the y axis. In which case get out your Pythagoras.

7. Jan 20, 2009

### -EquinoX-

I use the pythagorean theory to find the distance from the -4 and 3 charhea to the point (0, 2.00) only right?