Electric field on a point charge

AI Thread Summary
The discussion revolves around calculating the electric field at a specific point near three point charges. The user attempts to compute the electric field contributions from each charge but questions the accuracy of their final answer, which the system indicates is incorrect. They detail their calculations for the electric fields generated by each charge, specifying the distances used for each calculation. A key point of confusion arises regarding the distances applied for the middle and right charges in the electric field equations. The user seeks clarification on the correct distances to use for these calculations.
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Hello guys,
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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what is the distance you use for E2 and E3?
 
For E2 i.e the middle one, I used just 1.01 cm (actually 0.0101 m) and for E3 4cm + 1.01 cm, which is 0.0501 m.
 
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