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Electric Potential Integral Question Confused

  • Thread starter lorx99
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  • #1
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Homework Statement


upload_2018-10-6_15-56-57.png


Homework Equations


E=KQ/R^2

The Attempt at a Solution


I'm kinda confused at what the question is asked. It is in terms of x, but I thought the integral for potential is V=int(Edr)? Also, should it be integration starting from infinity? Why is the integration from -2 to 3?. I'm just confused by the wording...
 

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Answers and Replies

  • #2
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Potential due to a point charge is given by
V=Kq/R
You can use this to write potential due to a small element and then integrate.
 
  • #3
kuruman
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First look at the five integrands. You can discard some of them because they have the wrong numerator. This means you have to find the correct numerator.

Then look at the denominators of the integrals that passed the previous test. The integrand is the contribution to the potential from charge ##dq## placed at point ##x## along the rod. This includes the ends. Substitute the positions of the ends of the rod for ##x## and see if you get the potential at ##x=5~m## from a point charge placed there.
 
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