Two EE questions -- nodal analysis and circuit modeling 1. The problem statement, all variables and given/known data 2. Relevant equations I was given R1, R2, and Iα(t), the time for the switch to closed (50μs<=t<=100μs) The question is asking about the energy associated with 2 sources and dissipated in R1, R2. 3. The attempt at a solution For the 1st question, part should be ok for me. But i have no idea on how to start the part b). take integration for Iα(t) (since Iα(t)=da/dt) , then obtain a i=(-1/5)e^-500t but what value for the integrals? integrated from t = 50μs to 100μs? or from t = 0μs to 200μs ? then "I" can be found? E=Pt, = (IV)t. What value of t will be used here for each source and resistor to find the energy? For Q4, totally no idea on it. It is about the topic of diode?