Notes on homework #4

Homework 4  has both some relatively easy and straightforward problems and some very difficult problems. From chapter 24, I think 30 is pretty easy; I noticed that in 14 and 16 you can actually just put the 1.6x10-19 in the denominator and MP will calculate the answer for you and give you full credit; in 37 something is open 20% of the time, ask about that if you want…

From chapter 25: 18 and 19 are pretty straightforward I think. 37 has to do with capacitors and resistors in equilibrium. 74 is related to what we did in class yesterday. V(t), I(t) and Q(t)  will all have that exponential form for their time dependence.

Problems 61 and 62 involve the dynamics of capacitors  and they are really difficult.   They both involve exponential time dependence very similar to what we derived  in class yesterday (Monday).   In  case you want to do those problems, and you don't have to,  I  enclose here some notes on those problems. They include more detail in the derivations then you really need to be able to do yourself, but I thought some people might be interested in seeing the time dependence derived in a fundamental way for these somewhat different situations.

Please feel free to post questions on any of the problems of homework 4 here.  also, please let me know if you think you might  benefit  from more time for homework 4.