Review of Circuit Elements
Resistor: VR = R I where I = Dq/Dt
Capacitor: VC = (1/C)q (from C = q/V)
We can make an analogy with mechanics:
q is like x; V is like F;
t is like t; L is like m;
I = Dq/Dt is like v = Dx/Dt; C is like 1/k (spring);
DI/Dt is like a = Dv/Dt; R is like air resistance.