boomvroomshroom wrote:In general the event is just so painful to study for because they literally can just ask you anything, and most people don't know much about it anyway (even if they're geology majors or whatever because no one is really sure what to ask).
Last year the Nationals test was pretty reasonable, but I remember our regionals test was pretty crazy. The entire thing was made up of calculation-based word problems, and about a quarter of them were just borderline geology-based. The math itself wasn't hard, but it took a lot of reasoning skills (we had never seen those types of problems before and so we had to draw out and derive the formulas ourselves).
Don't get me wrong, Geomaps is a great event, but it's just so unpredictable.
Yes and no. I've done the event for 3 years in NYS, where it originated. I think us original folk that have done it can say we've had it tough . Trust me, I know what you mean, but NYS Geomaps is uh...definitely made by someone who knows his stuff. My complaint has always been how broad the event has been, but it seems like nothing has changed much, if anything it's only gotten broader. At least it makes you appreciate geology! I say no only because by the third year...I kinda got the gist of what was gonna be asked (at least leagues ahead of when I first did it).
B: Crave the Wave, Environmental Chemistry, Robo-Cross, Meteo, Phys Sci Lab, Solar System, DyPlan (E and V), Shock Value
C: Microbe Mission, DyPlan (Fresh Waters), Fermi Questions, GeoMaps, Grav Vehicle, Scrambler, Rocks, Astro
Grad: Writing Tests/Supervising (NY/MI)
Can someone please verify which is the correct formula to use when finding true thickness? The formula my partner and I used is AB= WsinD + HcosD which we got from https://www.uwgb.edu/dutchs/structge/SL47TrueThk.HTM. however, at an invitationals, the formula the proctors used for the problem was AB = WsinD + HsinD.
Thanks in advance!
Metasepia_pfefferi wrote:Can someone please verify which is the correct formula to use when finding true thickness? The formula my partner and I used is AB= WsinD + HcosD which we got from https://www.uwgb.edu/dutchs/structge/SL47TrueThk.HTM. however, at an invitationals, the formula the proctors used for the problem was AB = WsinD + HsinD.
Thanks in advance!
It should be WsinD+HcosD. If you've taken geometry, sinD=AC/W and cosD=CB/H, thus WsinD=AC and HcosD=CB; AC+CB=AB=WsinD+HcosD.
The graders either got that one wrong, or perhaps used a different angle? (Perhaps you thought they were using D, but in reality they were using the complement of D on the other side...)
Metasepia_pfefferi wrote:Can someone please verify which is the correct formula to use when finding true thickness? The formula my partner and I used is AB= WsinD + HcosD which we got from https://www.uwgb.edu/dutchs/structge/SL47TrueThk.HTM. however, at an invitationals, the formula the proctors used for the problem was AB = WsinD + HsinD.
Thanks in advance!
It should be WsinD+HcosD. If you've taken geometry, sinD=AC/W and cosD=CB/H, thus WsinD=AC and HcosD=CB; AC+CB=AB=WsinD+HcosD.
The graders either got that one wrong, or perhaps used a different angle? (Perhaps you thought they were using D, but in reality they were using the complement of D on the other side...)
Apparently you also have to take into account whether the ground and bed are sloping down in the same direction or in opposite directions... I think in the latter case, above formula works, but in the former case, you take the difference of WsinD and HcosD, not the sum.
Conestoga HS (2013-15)
Haverford HS (2011-13)
Haverford MS (2010-11)
Metasepia_pfefferi wrote:Can someone please verify which is the correct formula to use when finding true thickness? The formula my partner and I used is AB= WsinD + HcosD which we got from https://www.uwgb.edu/dutchs/structge/SL47TrueThk.HTM. however, at an invitationals, the formula the proctors used for the problem was AB = WsinD + HsinD.
Thanks in advance!
It should be WsinD+HcosD. If you've taken geometry, sinD=AC/W and cosD=CB/H, thus WsinD=AC and HcosD=CB; AC+CB=AB=WsinD+HcosD.
The graders either got that one wrong, or perhaps used a different angle? (Perhaps you thought they were using D, but in reality they were using the complement of D on the other side...)
Apparently you also have to take into account whether the ground and bed are sloping down in the same direction or in opposite directions... I think in the latter case, above formula works, but in the former case, you take the difference of WsinD and HcosD, not the sum.
In general you shouldn't be using formulas; just draw a picture and use geometry.
boomvroomshroom wrote:
It should be WsinD+HcosD. If you've taken geometry, sinD=AC/W and cosD=CB/H, thus WsinD=AC and HcosD=CB; AC+CB=AB=WsinD+HcosD.
The graders either got that one wrong, or perhaps used a different angle? (Perhaps you thought they were using D, but in reality they were using the complement of D on the other side...)
Apparently you also have to take into account whether the ground and bed are sloping down in the same direction or in opposite directions... I think in the latter case, above formula works, but in the former case, you take the difference of WsinD and HcosD, not the sum.
In general you shouldn't be using formulas; just draw a picture and use geometry.
Yup, pretty much. If you want that done for you, though (or want to save time), take a gander at this picture
Last edited by elephantower on Tue Mar 10, 2015 8:50 pm, edited 1 time in total.
kmbrgandhi3 wrote:Hey: at the invitationals I attended this year, we generally did well on 'informational' questions and could solve the majority of the stereonet/mathematics-based problems. However, there were always a couple more mathematically focused questions that tripped us up – looking back at the problems, I have been able to figure out how to do all of them with sufficient time, but I'm wondering if there is a good bank for problems that is decently comprehensive. I don't want to get tripped up similarly at states, and I think that having been exposed to more problems would help my time efficiency.
I know that this question is probably impossible to answer completely, since I imagine that there isn't one particular website or book with all of the problems that we need to know – but if people could direct me to good sets of problems that generally cover the topics in question, it would be much appreciated.
Not to toot my own horn, but have you solved all my practice test problems on the test exchange? They're very mathematical, and give a general overview of the skills required in this event.
kmbrgandhi3 wrote:Hey: at the invitationals I attended this year, we generally did well on 'informational' questions and could solve the majority of the stereonet/mathematics-based problems. However, there were always a couple more mathematically focused questions that tripped us up – looking back at the problems, I have been able to figure out how to do all of them with sufficient time, but I'm wondering if there is a good bank for problems that is decently comprehensive. I don't want to get tripped up similarly at states, and I think that having been exposed to more problems would help my time efficiency.
I know that this question is probably impossible to answer completely, since I imagine that there isn't one particular website or book with all of the problems that we need to know – but if people could direct me to good sets of problems that generally cover the topics in question, it would be much appreciated.
Not to toot my own horn, but have you solved all my practice test problems on the test exchange? They're very mathematical, and give a general overview of the skills required in this event.
Do you remember what those problems were? Generally when there's "weird" math problems (that diverge from stereonets and basic stuff), they have no specific "solution format". But we can probably figure it out if we stare at it for long enough.
kmbrgandhi3 wrote:Hey: at the invitationals I attended this year, we generally did well on 'informational' questions and could solve the majority of the stereonet/mathematics-based problems. However, there were always a couple more mathematically focused questions that tripped us up – looking back at the problems, I have been able to figure out how to do all of them with sufficient time, but I'm wondering if there is a good bank for problems that is decently comprehensive. I don't want to get tripped up similarly at states, and I think that having been exposed to more problems would help my time efficiency.
I know that this question is probably impossible to answer completely, since I imagine that there isn't one particular website or book with all of the problems that we need to know – but if people could direct me to good sets of problems that generally cover the topics in question, it would be much appreciated.
Not to toot my own horn, but have you solved all my practice test problems on the test exchange? They're very mathematical, and give a general overview of the skills required in this event.
Do you remember what those problems were? Generally when there's "weird" math problems (that diverge from stereonets and basic stuff), they have no specific "solution format". But we can probably figure it out if we stare at it for long enough.
Pretty much, as long as you know all the basic trig formulae relating apparent dip to true dip to angle of obliquity, etc.
Quick question: what's the most complicated problem you've ever seen, ever? Mine was actually at a regionals, where we had to calculate original apparent dip with like three faults in the way. State and Nats didn't even come close XD
. Trust me, I know what you mean, but NYS Geomaps is uh...definitely made by someone who knows his stuff. My complaint has always been how broad the event has been, but it seems like nothing has changed much, if anything it's only gotten broader. At least it makes you appreciate geology! I say no only because by the third year...I kinda got the gist of what was gonna be asked (at least leagues ahead of when I first did it).
