# 2 Problems involving electric field and work

1. Nov 6, 2015

### nutella

1. The problem statement, all variables and given/known data
Excuse my excellent paint skills
http://imgur.com/PbXdlOW
If the work done by a charge from z to y is W. Would the work be different if it was from z to x then to y.
2. Relevant equations
W=vQ

3. The attempt at a solution
I said it would be the same because delta v would be the same in the end

1. The problem state, all variables and give/known data
http://imgur.com/RkG05ph

What is the electric field at the point z and what is the direction
2. Relevant equations
E=kq/r^2
3. The attempt at a solution
I assume the positive and negative would cancel each other out. The distance between the charge and the center is d rad(2)/2 so the charge for one of them would be KQ/(2d^2/4)= 2KQ/d^2 then you just multiply that by 2 because there is two charges, but i don't know the direction

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2. Nov 6, 2015

### Staff: Mentor

The fact that you don't know the direction in the last problem is an indication that you did something wrong. Can you justify

3. Nov 7, 2015

### nutella

My teacher showed us a problem where the opposite corners were opposite charges and he said the electric field at the middle is zero.

4. Nov 7, 2015

### Staff: Mentor

What happens if you put a test charge in the middle?