MD six min solutions

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r_mojo1

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Is anybody using the six min solutions for MD. I have the fluids and thermal and think is ok. Let me know if you want to trade questions.

 
I didn't end up getting it bc the reviews for it were so bad. Some people said they found it useful tho. For me, it would be too frustrating working thru problems that were filled with errors and incorrect solutions.

 
MD 6 min solutions sucks. The problems are exponentially harder than the real thing. The best MD problems I think were in the practice exams.

 
Good to know. I'll concentrate on the NCEES exams. Although I did buy the 6MS for T/F and HVAC to brush up on some more breadth type problems.

 
MD 6 min solutions sucks. The problems are exponentially harder than the real thing. The best MD problems I think were in the practice exams.
I disagree, I thought that 6MS was representative, NCEES practice was slightly easier and Lindeburger was a flippin joke.

I couldn't imagine doing all that studying and expense to not buy one more book. Devour all the info you can afford/get your hands on. however, after I passed, I got to expense everything. If you dont get to expense, I am pretty sure you can at least write it off on your taxes.

 
I thought the MD 6MS was great practice even though the problems were harder and it had all kinds of errors in the solutions. I can say taking that gave me more confidence than any of the other practice exams I took.

 
I borrowed these books from a friend and studied them. I think they were way better than the problems in the practice problem books. The problems were more representitive of what is on the test.

 
Anyone working these? If so let me know your answer to problem 19...I definitely do not agree! I mean really? Their answer is just not logical, IMO.

 
I agree with the solution

A = 5e-4 m^2

rho = 8602 kg/m^3

M = .0015 kg

V = M/rho = 1.744e-7 m^3

depth = V/A = 3.488e-4 m

depth/time = 3.488e-4 m/72h = 4.8438 m/hr = 42460 e-6 m/yr

 
I agree with the solution

A = 5e-4 m^2

rho = 8602 kg/m^3

M = .0015 kg

V = M/rho = 1.744e-7 m^3

depth = V/A = 3.488e-4 m

depth/time = 3.488e-4 m/72h = 4.8438 m/hr = 42460 e-6 m/yr
3.488e-4 m/72 hr = 4.844e-6 m/hr....unless I'm calculating wrong.

I originally got A for the answer, which is much more logical than 42,400 micrometers per year. This equates to about 1670 mils per year....and in the industry I work in, corrosion of about 4-6 mils is typical for "real life" corrosion.

 
I did figure out what I was doing wrong...and I agree with the answer, but it's just a crazy amout of corrosion I think.

 
If you don't mind to restate the problem (since I don't have the book), I may be able to shed some light on whether the amount of corrosion is reasonable or not.

 
Problem 19 reads: A nickel plate is tested in a corrosive environment. The density of the nickel is 8602 kg/m^3. A 5 cm^2 sample is exposed for 72 hours and loses 1.5 g. The predicted material loss for the nickel plate in use is most nearly ? micrometers/year.

1.67 inches is equal to the answer of 42,400 micrometers. I think I'd pick another material.

 
Was tempted to get 6 minute, but Amazon reviews were horrible. I especially didn't like the part about how thin the book was. Guess I'll find out in April how that worked out for me...

NHale

 
SMott,

Your answer is correct, 42,432 um/yr. It is possible that the purpose of the problem is to be able to determine if the corrosion rate is acceptable or not. Clearly, it is not, but that is not necessarily evident by the test results.

Industry example: I had a customer request a tank designed for 0.5 psig vacuum. This does not seem like an unreasonable request on its own. However, the tank was to be 170 ft in diameter. I am sure that the problem is evident.

 
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