I have the EERM v8, but I didn't get the practice problems. Do you think that's a good idea? With books/resources I have, I should have plenty of problems to work, but if the EERM practice problems are more representative of the exam (i.e. NCEES Sample Exam) then I'll order it.
Unfortunately, my wife planned a Disney vacation without regard to my studying from March 31-April 6. So basically I'll have a week to forget everything, and then 10 days to cram before the test. Since I've taken that vacation, I don't have enough time to take any more time off during exam week. Oh well, I'll make the most of it.
Getting back to problem 102 in NCEES sample exam. As usual, I went to work it last night and it turns out the way they solved it isn't even close to being specified in the EERM. They solved for the z parameters first, then changed them to y-parameters. I don't have my books in front of me, but I couldn't find the solution they gave expressed in the EERM. That's what I'm finding a lot of and its very frustrating. Don't get me wrong, I understand the solution from NCEES and I can build from that, so that's good. Its just frustrating when you look through all your books and can't find the way to do it. I'm still a little gray on it though.
Are you any good with control systems? 534 and 535 are kicking my butt.
For 534, just multiply the boxes and you get: 50 / (20s^2 + 40s) as a replacement for the 3 boxes. Now you have one box with feedback, so you want to use the equation C(s)/R(s) = G(s) / (1 + G(s)) solve this until you have a polynomial in the denominator that has a 1 as the coefficient for s^2. (According to the answer you have: 2.5 /(s^2 + 2s + 2.5). If you look at equation 31.68, page 31-14, gives the definition for damping ratio. So looking at the equation in the denominator, you see that 2 = 2 * damping_ratio * Wn. You know Wn^2 = 2.5. So plug it in and solve for damping ratio.
For 535, looking at the answer, you only need to focus on the polynomial in the denominator, so you have s^2 + 3s + (2+k). In order for this to be stable you do not want (2+K) to be negative, so K > =-2. This is using the Hurwitz Test (page 64-12) or the more complicated Routh Criterion (same page.)
Hope this helps.
(I would highly recommend the practice book. My theory is your mind doesn't learn the material unless your fingers do the work. If you don't "do it" you will not "remember it".