(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 3.17 μC and a -2.19 μC charge are placed 3.65 cm apart. At what point along the line joining them is the electric field zero? Assume that the first charge is at the origin and the second charge is at +3.65 cm.

2. Relevant equations

E = K(q) / r^{2}

Ep = E1 + E2

0 = E1 + E2

-E1 = E2

Since one is negative and the other is positive they would really work together making it E1 + E2, then -E1 = E2

3. The attempt at a solution

Ep = E1 + E2

0 = E1 + E2

-E1 = E2

-k(q1) / x^{2}= k(q2) / (r - x)^{2}

-(q1) / x^{2}= (q2) / (r^{2}- 2rx + x^{2})

-(q1)(r^{2}- 2rx + x^{2}) = (q2)(x^{2})

-(3.17e-6)(0.0365^{2}- 2(0.0365)x + x^{2}) = (-2.19e-6)(x^{2})

-(3.17e-6)(1.33e-3) - (7.30e-2)x + (x^{2}) = (-2.19e-6)(x^{2})

-(3.17e-6)^{2}2 + (7.30e-2)x - (4.22e-9) + (2.19e-6)x^{2}= 0

(-9.80e-7)^{2}2 + (7.30e-2)x - (4.22e-9) = 0

x = -b +/- √[b^{2}- 4ac / 2a

x = [-(7.30e-2) +/- √(7.30e-2)^{2}- (4)(-5.36e-6)(-4.22e-9)] / 2(-9.80e-7)

x = [-(7.30e-2) +/- (5.33e-3)] / [-1.96e-6]

Sorry if that's hard to read. But after i did all this, i got answers way to big to even be close. They were easily in the 10s of thousands. What did i do wrong?

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# Homework Help: Electric Field Between two Charges Equals 0

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