1. The problem statement, all variables and given/known data https://wug-s.physics.uiuc.edu/cgi/courses/shell/common/showme.pl?cc/DuPage/phys2112/summer/homework/Ch-21-Gauss-Law/charged_sheet/sheet.gif [Broken] An infinite nonconducting sheet of charge, oriented perpendicular to the x-axis,passes through x = 0. It has area density σ1 = -3 µC/m2. A thick, infinite conducting slab, also oriented perpendicular to the x-axis, occupies the region between x = a and x = b, where a = 2 cm and b = 3 cm. The conducting slab has a net charge per unit area of σ2 = 5 µC/m2. (a) Calculate the net x-component of the electric field at the following positions: x = -1, 1, 2.5 and 6 cm. (b) Calculate the surface charge densities on the left-hand (σa) and right-hand (σb) faces of the conducting slab.You may also find it useful to note the relationship between σa and σb. 2. Relevant equations Gauss' Law E = σ/2*epsilon 3. The attempt at a solution PART A -- For x = -1 cm, I summed the two individual electric fields. For the sheet I said the electric field would be positive since the sheet's charge is negative so the field lines are going in the positive x direction (towards the sheet). For the slab I said the electric field was negative since the slab had positive charge, so the field lines are going away from the slab (i.e. in the negative x direction) -- For x = 1 cm, same logic. I summed both individual fields again. This time both were negative since field lines for both the sheet and the slab were headed in the negative x direction. -- For x = 2.5 cm, the electric field is zero since it is within the conductor and conductors have zero electric fields within them. -- For x = 6 cm, I only used the electric field of the slab, since I thought it would block the field of the sheet. However I said it had a sigma of 2 µC/m2, since 3 µC/m2 had to be on the left side to balance out the -3 µC/m2 of the sheet. PART B Since σ = E*epsilon, I multiplied the value of the electric field at 1 cm by epsilon to get the value of σa. I said the charge was positive since it had to counteract the negative area density of the sheet. For σb, I used charge conservation (i.e. 5 - σa). My question to everything above is: is my logic correct? I really had no idea on how to do the problem so I started taking wild guesses and plugging in numbers. Thankfully all the answers above are right, but come time for a test I want to KNOW how to do the problem, rather than rely on blind luck. Thank in advance for correcting any of my incorrect thinking!