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Were is the electric field zero?

  • Thread starter blackblanx
  • Start date
  • #1
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Homework Statement



What is the net electric field intensity at the origin due to two charges Q1= 2[tex]\mu[/tex]C at (x=3,y=4) and Q2 = -10[tex]\mu[/tex]C at (x=6,y=-8). And where should a third charge of magnitude 5 [tex]\mu[/tex]C be placed so the net electric field at the origin is zero?

Homework Equations


E=KQ/R[tex]^{2}[/tex] [tex]\widehat{r}[/tex]

The Attempt at a Solution



I have found the first part of the question to be E= 3236[tex]\widehat{i}[/tex]-10069[tex]\widehat{j}[/tex] but I am not sure how you would find out were to place the third charge. Please help
 

Answers and Replies

  • #2
tiny-tim
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Hi blackblanx! :smile:

(have a mu: µ :wink:)
… And where should a third charge of magnitude 5 [tex]\mu[/tex]C be placed so the net electric field at the origin is zero?

I have found the first part of the question to be E= 3236[tex]\widehat{i}[/tex]-10069[tex]\widehat{j}[/tex] but I am not sure how you would find out were to place the third charge. Please help
The third charge will have to supply a field of minus E. :wink:
 
  • #3
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Hi blackblanx! :smile:

(have a mu: µ :wink:)


The third charge will have to supply a field of minus E. :wink:
but what are the coordinates of where that charge should be placed?
 
  • #4
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oh wait never mind i think i got it know thanks it would just be the negative of the electric field vector divided by k(5[tex]\mu[/tex]C)
 
  • #5
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Forget I realized that does not work any ideas of how to find the coordinates?
 
  • #6
tiny-tim
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It'll be on the line in the direction of E, at the distance appropriate to the given strength. :smile:
 
  • #7
16
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ok thanks
 

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