How Much Charge Does a 3cm Section of a Charged Line Hold?

[sckeen1988]

The electric field 0.475m from a very long uniform line of charge is 830 N/C.

How much charge is contained in a section of the line of length 3.00cm?

My solution:
the Electric field from an infinite plane is

E=σ/(2*ε0), so σ=E*ε0*2=1.47*10^-8

3.00cm=.03m

.03*1.47*10^-8=4.41*10^-10

This answer is showing to be wrong

 

[sckeen1988]

Just realized my problem was that my work was for a plane, not a line of charge. I'm not sure how to solve this for a line of charge though

 

[vela]

A line charge has a cylindrical symmetry, so apply Gauss's Law using a cylinder as your Gaussian surface.

 

[sckeen1988]

Thanks for the help, forgot to reply at the time due to my astonishment that I had not thought of that.