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**[SOLVED] Distance between two charges where field strength = 0**

**1. Homework Statement**

Two particles having charges q1 = 0.500 nC and q2 = 9.00 nC are separated by a distance of 2.00 m.

At what point along the line connecting the two charges is the total electric field due to the two charges equal to zero?

**2. Homework Equations**

[tex] E = \frac{1}{4 \pi \epsilon _0}\frac{q}{r^2} [/tex]

I have reduced this two:

[tex]\frac{q_1}{r_1^2} = \frac{q_2}{r_2^2}[/tex]

**3. The Attempt at a Solution**

putting in the variables:

[tex]\frac{0.5*10^{-9}}{r_1^2} = \frac{9.0*10^{-9}}{r_2^2}[/tex]

I can rearrang to get:

[tex]\frac{r_2^2}{r_1_2} = \frac{9.0*10^{-9}}{0.5*10^{-9}}[/tex],

and:

[tex]\frac{r_2^2}{r_1_2} = 18 [/tex]

But I am not sure how to get the right distance to the actual point?

TFM