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Calculating the electric field 
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#1
Oct507, 09:45 PM

P: 177

1. The problem statement, all variables and given/known data
What are the strength and direction of the electric field at the position indicated by the dot in the figure? 2. Relevant equations E_{dipole} = ~ [1/(4πε_{0})] * [2p/r^{3} ] on the axis of an electric dipole E_{dipole} = ~ [1/(4πε_{0})] * [p/r^{3} ] in the plane perpendicular to an electric dipole 3. The attempt at a solution Which equation should I use?? Thanks 


#2
Oct507, 11:23 PM

Sci Advisor
P: 1,199

Neither. Your equations only apply if the two charges in the dipole are much closer together than the distance r from the dipole.



#3
Oct607, 05:36 PM

P: 177




#4
Oct607, 06:21 PM

P: 177

Calculating the electric field
my textbook uses these forumulas...so i tried the problem using them
so here is my process: p = qs s=0.1 q=1*10^{9} p=1*10^{10} 1/(4πε_{0}) = 9*10^{9} r=0.05m plugging everything into the second equation {[1/(4πε_{0})] * [p/r3 ]}, i get 7200, but this is incorrect 


#5
Oct607, 06:23 PM

Sci Advisor
HW Helper
P: 1,275




#6
Oct607, 06:39 PM

P: 177

E=[1/(4??_{0})]*[q/r^{2}] using the two charges: q_{1}=1*10^{9} q_{2}=1*10^{9} and their respective distances: r_{1}=0.05 r_{2}=0.0125^{0.5} (square root) and doing all calculations, and then adding the two charges (3600 and 720) gives me 2880, which is incorrect... 


#7
Oct707, 12:00 PM

P: 177

lol so yea....umm...any help?



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