Gausses Law

[ice87]

http://noether.physics.ubc.ca/Physics153/assignt222k6.pdf
^ number 2.

I dont get this problem. if the plastic sheets are non-conducting, does that mean the electric field cant penetrate the sheets? and how should i do this problem?

[Tom Mattson]

That should be explained right in your textbook. You have electric field vectors that are parallel to both normal vectors (both sides of the sheet).

See this website and look at the picture with the caption "Sheet of charge".

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/gaulaw.html#c4

[lightgrav]

Nonconducting means that the charges stay where they're put.
Since they don't tell you a dielectric constant (polarization \kappa),
presume that there is ZERO polarization in the material ...
the E-field is completely uneffected by the plastic (but NOT the charges!).

Start by enclosing all 4 charged surfaces
(but not the negative charge at infinity ...)

Incidently, the distance of the point from the surfaces is unimportant.