Hi, I don't get how to do this at all because I missed the lesson so could someone please help me? I appreciate it a lot! First problem: http://img55.imageshack.us/img55/9403/physics8tl.jpg [Broken] a) if the switch closes, what is i1? i1 is current at that position b) graph v2 versus t graph c) after a long time, if the switch opens, what is i2? d) calculate Q (charge) of the capacitor e) calculate U (potential energy) of the capacitor Second problem: There is a capacitor with two plates with very large surface area. They are set d distance apart and have equal but opposite charge densities. a) diagram the current through the plates (no idea how to do this). b) If a dielectric is added, does the electric potential increase, decrease, or stay the same? What mechanism causes this effect? (I think it goes down because of the q=cv formula but i dunno what mechanism). Thanks a lot!