What is the net electric field at x = + 2.0 cm?

AI Thread Summary
The discussion revolves around calculating the net electric field at x = +2.0 cm due to two point charges: +3.5 µC at the origin and -3.5 µC at x = 10.0 cm. The user initially computes the electric field contributions from both charges but receives an incorrect result when verifying the answer. They calculated the electric field at x = -2.0 cm as 76,562,500 N/C to the left but are uncertain about the accuracy of this value. The conversation highlights confusion over the calculations and the need for clarification on the correct approach to find the net electric field. Accurate calculations and understanding of electric field direction are essential for resolving the discrepancies in the answers.
mikep
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Can someone please help me with this question?
Two point charges lie on the x axis. A charge of + 3.5 µC is at the origin, and a charge of -3.5 µC is at x = 10.0 cm. What is the net electric field at x = -2.0 cm? What is the net electric field at x = + 2.0 cm?

for the first one i did
k q/r^2
(9 x 10^9) (3.5 x 10^-6)/(0.02m)^2 = 78750000 N/C
(9 x 10^9) (-3.5 x 10^-6)/(0.12m)^2 = -2187500
78750000 - 2187500 = 76562500N/C
can someone please tell me what I'm doing wrong?
 
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what seems to be the problem?
do the solutions have a different answer?:S
 
yeah when i entered this value in, i got it wrong
 
I just tried the first question, and I got 7656250N/C (to the left). I'm sure that's the answer...
 
how do you get that?
 
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