# Electric field of an infinite line charge and a point charge

#### amilkovi

Electric field of an infinite line charge and a point charge!!!

1. Homework Statement
An infinite line charge with linear charge density $$\lambda$$=2.0$$\mu$$C/m lies along the y-axis. A point charge of 8.0 $$\mu$$C is locate at (x,y)=(-1.0m, 2.0m). Find (a) the electric field at (x,y)=(1.0m, 2.0m) (b) Find the force on a charge of -2.0$$\mu$$C placed at (x,y)=(1.0m, 2.0m).

I would love if someone could point me into the right direction here!
2. Homework Equations

3. The Attempt at a Solution
I believe I'm gona have to add the electric field of both the line and the point charge at the point (1.0m, 2.0m) for part (a)? Then for part (b) do the same except apply the negative charge at the same point and subtract its electric field?
1. Homework Statement

2. Homework Equations

3. The Attempt at a Solution

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#### vela

Staff Emeritus
Homework Helper
Re: Electric field of an infinite line charge and a point charge!!!

I believe I'm gona have to add the electric field of both the line and the point charge at the point (1.0m, 2.0m) for part (a)?
Yes.
Then for part (b) do the same except apply the negative charge at the same point and subtract its electric field?
No. The negative charge feels a force due to the fields of the other charges. You don't need to take into account the field due to itself.

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