Hello everyone. I'm so close to getting this problem done but i can't get the last part right!(adsbygoogle = window.adsbygoogle || []).push({});

THe problem is the following:

Two long, charged, thin-walled, concentric cylinders have radii of 3.0 and 6.0 cm. The charge per unit length is 4.9 10- 6 C/m on the inner shell and -8.5 10-6 C/m on the outer shell.

(a) Find the magnitude and direction of the electric field at radial distance r = 4.8 cm from the common central axis. (Take radially outward to be positive.)

I found this by using: E = [tex]\delta[/tex]/2PIEor;

E = (4.9E-6)/(2PIEo(.048m) = 1835826.8 N/C

(b) Find the magnitude and direction of the electric field at r = 8.5 cm, using the same sign convention.

I can't seem to figure this part out. I tr4eid doing the following:

I added up the E field @ 3.0cm and @ 6.0cm to get 389644.9 but didn't know what do it with it from there. So i tried, just using the same method as above in part (a) but insteed of using .048m i used .085m and i got -1798361 N/C which was wrong. Any help would be great!

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# Homework Help: Stuck! I can't find the E field outside cylinder, but inside i found!

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