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I have a question which I think I solved it right but I don't understand why the final answer is wrong.

Here's the problem: Consider three charges as shown. k is 8.98755 * 10^9 N m^2/c^2. What is the electric field at a point 1.01 cm to the left of the middle charge? Ans. in N/C.

For the figure: O---------O-------O; seems like this. The charges are: (beginning from the left) 7.35, 4.32, -3.42 microCulombs. Distances The left to Middle is 4.92 cm and Middle to Right is 4 cm.

So, the most left is positive, the middle is positive and the one in the right is negative. The point P is 1.01 cm to the left of the middle particle.

What I did:

E1 = [k*(7.35*10^-6)]/(0.0492-0.0101)^2

E2 = the same thing, with its parameters (but this is toward -x-axis)

E3= the same, toward + x-axis

Then I add this up and I get approx. -3.2517*10^8 N/C

Actually this is not the answer (at least the System says so)

Please take a look at this thing, maybe there's sth tiny I don't get.

Thanks

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# Homework Help: Electric field on a point charge

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