Problem $1$ For each of the below first$-$order circuits, determine the voltage v$($t$)$ for t $>0$ assuming that the circuit stores zero initial energy at t $=0.($a$)($b$)$ Answer: $($a$)$ v$($t$)=16$e $$t$/2$ and $($b$)$ v$($t$)=24(1$ e $$t $),0<$ t $<130$