I understand that when the switch is open, the capacitor acts like an open circuit & therefore the current in the capacitor branch would be equal to 0. When I solved the circuit using nodal analysis, I realized that the 2k ohm and the 4k ohm are in series.
How would I look at the circuit and automatically realize they're in series? Because realizing they're in series would result in a much easier answer using KVL. 5(-10) + Vc - 4(6/6) = 0