How Do Charge Locations Affect Electric Field Calculations?

AI Thread Summary
The discussion focuses on calculating the electric field at the origin due to three charges with specified magnitudes and coordinates. The user initially computed the electric field contributions from each charge using the formula E = (kq)/r², resulting in specific values and angles for each charge. However, the final calculated components of the electric field did not match the expected results. It was identified that the error stemmed from incorrect angle calculations for one of the charges, specifically E2, which should be adjusted to 35º below the +x-axis. Correcting this angle is essential for obtaining the accurate total electric field values.
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"Three charges, +2.5 microC, -4.8microC, and -6.3microC, are located at (-0.20m, 0.15m), (0.50m, -0.35m), and (-0.42m, -0.32m) respectively. What is the electric field at the origin?"
Using the coordinates, I found that r12 = 0.0625 m2, r22 = 0.3725m2, and r32 = 0.2788m2. I then plugged that into the equation E = (kq)/r2, where k = 9 * 10^9.

Using that I found:
E1 = 3.6 * 10^5 N/C at 37º below the +x-axis.
E2 = 1.2 * 10^5 N/C at 35º above the -x-axis.
E3 = 2.0 * 10^5 N/C at 37º below the -x-axis.
Then the final components of the total Electric Field is:
Ex = 2.9 * 10^4 N/C
Ey = -2.7 * 10^5 N/C

However, the answer is 2.2 * 10^5 N/C for x, and -4.1 * 10^5 N/C for y. What am I doing wrong?
 
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You problem solving approach looks correct.

Maybe you went wrong in the arithemtic (+/- signs)? Or perphaps you've not calculated the angles correctly?
 
siddharth said:
You problem solving approach looks correct.

Maybe you went wrong in the arithemtic (+/- signs)? Or perphaps you've not calculated the angles correctly?
It was the angles.
E2 should be = 1.2 * 10^5 N/C at 35º below the +x-axis.
 
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