I think I made some headway. For the first question the electric field is not constant over the suface nor is it everywhere perpendicular to dA so we can't use the flux = ∫E*DA half of Gauss' law. We can use the right side, i.e. flux = Qcontained/eo. Multiply each charge density by the height...
Homework Statement
http://smartphysics.com/Content/Media/Images/EM/03/h3_lineD.png
charge density 1 = .00029 C/m
charge density 2 = -.00087 C/m
h = .116 m
a = .094 m
a) What is the total flux Φ that now passes through the cylindrical surface of height h=.116 m? Enter a positive number if...