1. Feb 8, 2004

### nautica

The electric field at a distance of 10 cm from an isolated point charge of 2 x 10^-9 C is:

A)1.8 N/C
B)180 N/C
C)18 N/C
D) 1800 N/C
E)none of these

This is the formula I used Q=rv/k

so (2x10^-9 C)(9x10^9 Nm^2) / .1 m C^2

I am getting 180 N m/C - I have an extra m in the equation, which would make it none of the about. Evidently I am doing something wrong.

Thanks
Nautica

2. Feb 8, 2004

### jamesrc

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

3. Feb 8, 2004

### gnome

You want E, not V.

For a point charge:

E = kq/r^2

4. Feb 8, 2004

### nautica

1800 N/C, thanks, nautica