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Continuous Charge Distributions

  • Thread starter WarpSpeedo
  • Start date
  • #1

Homework Statement



A charge lies on a string that is stretched along an x axis from x = 0 to x = 3.00 m; the charge density on the string is a uniform 9.00 nC/m. Determine the magnitude of the electric field at x = 8.00 m on the x axis.

Homework Equations


[itex]
\int_0^3 kλ/(8-x)^2\,dx
[/itex]

The Attempt at a Solution



k=8.99e9
λ=9

I know k and λ can come out of the integral leaving 1/(8-x^2). which gives me 9.44e-10 which webassign marks wrong.
 

Answers and Replies

  • #2
vela
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Your set-up looks fine, but I don't get anything close to the numerical answer you're getting.
 
  • #3
TSny
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The Attempt at a Solution



k=8.99e9
λ=9

I know k and λ can come out of the integral leaving 1/(8-x^2). which gives me 9.44e-10 which webassign marks wrong.
Are you thinking about the units for λ?
 
  • #4
Problem was the units for λ. Thanks for your help
 

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