Kaplan calculations

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Kaplan calculations

Postby pig » Tue Feb 06, 2018 3:53 am

pls also refer to attached.
and then there are lots of SDC, Site category D, V=S(DS)WIR etc. etc....
is this something we need to know. i just cannot imagine doing this level of math during. the exam particularly when those IBC tables are not even given (i think) ncarb during the exam.
anyone who can enlighten please~?
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Re: Kaplan calculations

Postby architerp » Tue Feb 06, 2018 11:13 am

pig wrote:pls also refer to attached.
and then there are lots of SDC, Site category D, V=S(DS)WIR etc. etc....
is this something we need to know. yes, why wouldn't it be? Especially if "there are lots of" it in the review guides. I cannot remember any topic that was in the SS study guide that I did not see on my exam. i just cannot imagine doing this level of math during. That's simple algebra. Brush up on trig, too. the exam particularly when those IBC tables are not even given (i think) ncarb during the exam. Individual questions may have a code excerpt to reference. You'll need to know how to decode the code. This is typical of all multiple choice sections.
anyone who can enlighten please~?


Regarding equations, the best bit of advice I found while studying is along the lines of "Understand what the formula variables mean and how they relate." For example in the above, I would ask myself, what happens to V if you doubled W or used site category C and what is significant about the definitions between site categories or what comprises W? There are example questions like that in the practice exams (a Kz coefficient question comes to mind). Those are the questions that are worth diving into.

Good luck!
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Re: Kaplan calculations

Postby jackstatic » Tue Feb 06, 2018 3:24 pm

So I just did this problem myself, and got (C) 167 Kips, which is correct BUT i just took a look at the answer that Kaplan gave and was not even remotely close to how I came up with the answer.

My Solution?
W/R
W = 1,000,000#/1000 = 1000kips
R = 6
1000k/6 = 166.7kips = 167kips

Kaplans Answer? I don't even know where to begin?

Was my math just conveniently lucky?

Edit: Spent some time with the answer, I now understand the formula Kaplan gives as an answer, conveniently the numbers worked out in my favor but that seems like a major trap on the actual exam!
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Re: Kaplan calculations

Postby pig » Tue Feb 06, 2018 11:33 pm

thank you architerp for your advice... i feel like it is going to be a fail for me... taking it tomorrow.
Prof DT did not even talk about the math of this in his course....

and jackstatic, how did you decide to divide W/R? Was there some kind of logic or formula to what you did?
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Re: Kaplan calculations

Postby architerp » Wed Feb 07, 2018 1:59 am

Positive vibes your way!

I felt unprepared going in, taking it, and after. But got a pass somehow.
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Re: Kaplan calculations

Postby jackstatic » Wed Feb 07, 2018 6:33 am

pig wrote:and jackstatic, how did you decide to divide W/R? Was there some kind of logic or formula to what you did?


Its probably absolutely wrong to do it this way so I don't recommend it, but I treated it as a shear wall/drag strut where I had the force and divided it by the rigidity... at least thats what I assumed the R meant.... This ONLY worked out because the other variables were 1s, and 1x1/6 is 0.167, so I effectively skipped some steps, whats dangerous about that tho is if the other variables were NOT 1 but say... .5x.5/6 you would get 0.0416 and the answer would be completely different.
Mathematically, dividing 1000/6 = 166.667, where as multiplying 1000x0.167= 167, again this only worked because the other variables were 1. I.E. I got lucky....

As for the kaplan answer, I get that we uses V=CsW, and that Cs = SdsI/R is 0.167, what i dont get is why they then compare it to Cs=Sd1I/TR which is 0.229. Is this a simple case of whichever number is less becomes the number we multiply by 1,000,000# (1,000k)?

What scares me about this question is that it's showing me I may not be ready for this test Sunday... ugh... I've been studying my balls off for the last month+ already failed this once, and was THINKING I was more prepared than last time.... I've taken off tmrw, friday, and saturday to just run practice exams, as I am wrapping up the Thaddeus re-watch tonight (got 2 hours left)... here's hopin!
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Re: Kaplan calculations

Postby architerp » Wed Feb 07, 2018 10:23 am

I get that we uses V=CsW, and that Cs = SdsI/R is 0.167, what i dont get is why they then compare it to Cs=Sd1I/TR which is 0.229...

They say Cs does not need to exceed Sd1/TR, if Sd1 = 0.55.
In the problem, Cs=Sd1I/TR=0.229.
Cs of 0.167 does not exceed 0.229, so use 0.167.
But, for example, if Sd1I/TR happened to equal 0.133, then the Cs=0.167 could be reduced to 0.133.

Good luck to you too!
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Re: Kaplan calculations

Postby pig » Thu Feb 15, 2018 9:22 pm

architerp wrote:Positive vibes your way!

I felt unprepared going in, taking it, and after. But got a pass somehow.


thank you architerp!!
i passed!!!!!
can't believe it.
still cannot believe this has come true.....
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