# Electric Field and Potential

1. Jul 14, 2017

### chopnhack

1. The problem statement, all variables and given/known data
An electric field is given by Ex = 2.2x + 5x2kNC-1. Find the potential difference between two points on the x axis at x = -2.0 m and x = 2.0 m

2. Relevant equations
∫5x2+2.2x from -2 to 2

3. The attempt at a solution
I got the answer of 27V.

Solution said - negative 27V

Thanks

2. Jul 14, 2017

### NFuller

Remember there is a negative sign in front of this integral since
$$\mathbf{E}=-\nabla V$$.

3. Jul 14, 2017

### kuruman

$\Delta V = -\int_{-2}^2{\vec{E} \cdot d\vec{s}}$
You left out the negative sign.

4. Jul 14, 2017

### chopnhack

yes, sadly I recall it now.....

5. Jul 14, 2017

### chopnhack

I was so happy to have found the proper way of handling it, I didn't recall the formula!!
Thanks all.