# Electric fields by point charges

1. Jan 26, 2010

### tkim90

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

*ignore the given numbers in the image, mine is different*

My numbers are:
Q1: 1nC
Q2: 8nC
Q3: -6nC

2. Relevant equations

$$E = \frac{kq}{r^2} * \hat{r}$$

3. The attempt at a solution
I only did (a1) so far. I know (a2) involves the exact same process (find r and plug it into the formula), except I don't know how to express it in coordinates since they're not on the same axes.

r = <? , ? , ?>
If i know r I think I could solve the problem.

thanks