Materials Science C

[Unome]

Hey ya'll! I'm planning on competing in Materials Science and I'm trying get study materials. The materials science wiki page seems to have issues loading images for some pretty important terms and subjects.
For instance, on the list of basic terms it comes up with this:
Stress - Force per unit area. Represented by Failed to parse (PNG conversion failed; check for correct installation of latex and dvipng (or dvips + gs + convert)): \sigma

I don't think it's a problem on just my end, so here's hoping this gets fixed soon or isn't too important
Thanks!

Yeah, Latex on the wiki has been broken for a while. If you want to see what it says, you can copy the last section (in this case \sigma) onto an online latex generator, such as this one.

[andrewwski]

According to Wikipedia creep begins to occur at around 35% of the melting point of a metal. On one of the tests in the exchange (New York State, Q5), it gives a metal with a melting point of 1240C and asks to find what temperature the metal will creep at. 35% of 1240 is 434, which made me choose A. The key says C. How does one get C? (231C)

Conversion to Kelvin gets pretty close.

Yep, remember that Celsius is NOT an absolute temperature scale, so doing multiplication/division in it is meaningless. You need to convert to Kelvin, do the multiplication, and convert back to Celsius.

Choice A was purposely put there for those who forgot to convert to Kelvin.

[BuildingFriend]

Hey everyone,
I've been decent at Materials science (only 3rd at Cornell and 6th at Yale ) but if there were any suggestions people had for cheatsheets that would be great. At the moment it's a bunch of condensed knowledge of general things, but that's pretty much down squat. We're working on getting more obscure knowledge like data tables, alloy names, graphs, charts, etc. If anyone had suggestions, pictures, or advice, that'd be great! Good luck to everyone this year!

[Avogadro]

What type of labs have people been seeing so far this year? The ones I've seen have been pretty consistently on the same couple of topics so it'd be nice to know what else people are making labs on.

[Skink]

What type of labs have people been seeing so far this year? The ones I've seen have been pretty consistently on the same couple of topics so it'd be nice to know what else people are making labs on.

My team got a really badly designed one (test in general, with the lab being the best part, unfortunately), something about literally dropping a liquid and measuring...some physical property...I'm pretty sure this was beyond the scope of the rules. I don't expect the activities to deviate far from the sample ones (see the Mat Sci ES page linked from the National site) unless the event supervisor has a background, at any rate.

[hearthstone224]

I had one where we had to measure flow rates of three liquids. I might've had the one you had, Skink. We had to invert a cup and measure how fast a liquid was flowing into a container, by recording how much liquid was left at 5 second intervals. You had to make a graph for each of the liquids and then calculate flow rate. The liquid would flow through a small hole we made in the container. It was a bit confusing to understand.

It wasn't badly designed in my opinion, rather just confusing.

Flow rate was also not part of the rules, which was kind of annoying as well. But hey, that's how you learn new things! It was in mL/sec.

[BuildingFriend]

One we had was the polymerization one by making goop out of glue and bleach or vinegar. Ironically, we did this for the science kids night- someone up there must have had a hand in it (pun anyone?)

[hearthstone224]

Wow, so they made you create a sort of goop? What did they make you do with it? (And nice pun)

Also, shall we talk written test? The stuff I got tested on the most was probably layering and names for layering- Know them!

ABAB = HCP and ABCABC = Cubic Closed Packing. I messed that up and didn't do too well. I'm actually holding my test right now. They also had one part where we were asked 16 or so materials and asked to classify each one either as polymer, metal, ceramic or composite.

[BuildingFriend]

Wow, so they made you create a sort of goop? What did they make you do with it? (And nice pun)

Also, shall we talk written test? The stuff I got tested on the most was probably layering and names for layering- Know them!

ABAB = HCP and ABCABC = Cubic Closed Packing. I messed that up and didn't do too well. I'm actually holding my test right now. They also had one part where we were asked 16 or so materials and asked to classify each one either as polymer, metal, ceramic or composite.

The goop was just observation- we didn't do it was I thought it was useless. It asked how the free radical polymerization happened in the initiation, propagation, and termination phases. About the written tests- I feel classification has to be down squat. There should be zero mistakes on that. Layering is just memorizing or tabling common values and stuff. The hardest parts are solving with math (TIME!) and answer labs perfectly in my opinion. Labs are the hard part while hard test is usually cheat sheated in my opinion. Does anyone have tests from Wright State or other invitationals? Please share in a PM or if they are on the test exchange, share please!

[hearthstone224]

Another quick question for you all. I would post on Question Marathon but it is a bit inactive and I've already posted a question on there, so here goes:

Balls' layers in cubic close packing which are in front of each other are
A) twelfth
B) tenth
C) thirteenth
D) sixteenth

I had no idea what this is asking and after a quick google, I still don't know. Can someone help me?