Fermi Questions C

[pb5754]

Can someone make a quick list of everything physics related I should know for this event? I'm kinda bad at physics.

Also, where do you find the 2013 Nats test?

Thanks!

The nats test was part of a trade I received sry. It is relatively basic with alotta gravity and estimating. Idk physics well (still taking bio :/)
Quick list: gravitational attraction
Gravitational acceleration (basically attraction)
Columbs law
Escape velocity
Kinetic energy
Size of black holes (very niche) it's 2GM/speed of light^2=radius
That's the ones off the top of my head probably alot I'm forgetting

Thanks!

[kenniky]

Also, where do you find the 2013 Nats test?

Thanks!

You can buy past Nationals test packets from soinc.org. I don't remember how much they cost but they are a good resource since they're, well, Nationals tests

Does anyone have an idea of what the top national scores would be per question (this obviously depends on the difficulty of the test)?

At UMich only one team got above a 3, everyone else was very solidly below 2.75

[Name]

Also, where do you find the 2013 Nats test?

Thanks!

You can buy past Nationals test packets from soinc.org. I don't remember how much they cost but they are a good resource since they're, well, Nationals tests

Does anyone have an idea of what the top national scores would be per question (this obviously depends on the difficulty of the test)?

At UMich only one team got above a 3, everyone else was very solidly below 2.75

Only 1 was above 3? Wow, I guess the test must have been pretty hard cuz a 3 average at UPenn I think wouldve landed around 20something. The test didn't seem ridiculously easy either, I was surprised when I got a 3.25 (which I would've expected to medal, I think medal was 3.4)

[Name]

Also a few more good physics equations-
Rotational inertia- MR^2
Rotational kinetic energy- rotational inertia times angular velocity (distance traveled/radius)^2 times 1/2
Centipedal force- MV^2/R
Frequency of light- Speed of light/wavelength
Effective mass of photon planck constant/wavelength
Energy of photon- frequency (planck constant)
Energy e=mc2
This and the post earlier should cover all/almost all the physics equations I've used, although I may be missing a few

[MingWeiHung]

What specific bio knowledge do you guys think we have to know?

[meierfra]

We just found out for our regional in 2½ weeks that Fermi will "concentrate specifically on Human Biology." I thought maybe they had a problem getting a good Fermi writer, so I offered someone who had written one for me. But I was told, no, they had a great Fermi writer, that their event supervisors fight over the opportunity to write Fermi, that this was decided based on some concerns raised. And then the usual stuff about how everyone found out at the same time, so it doesn't disadvantage anyone.

We have one Physics/Astronomy/Chemistry kid and one Biology/Stats kid and the Physics kid is definitely better at Fermi, but he'll probably be replaced by another Bio person for Regionals. He will definitely be disadvantaged.

I was just wondering if this happened to anyone else or if someone knows what concerns this is responding to.

[hippohungry]

What are some useful conversions we should know?

[Name]

What are some useful conversions we should know?

For conversations just study pretty much anything you can find and thier values in standard SI values

How do people study general estimating? (Like numbers of stray cats in US)

[mcmn1619]

What are some useful conversions we should know?

For conversations just study pretty much anything you can find and thier values in standard SI values

How do people study general estimating? (Like numbers of stray cats in US)

I think the idea is to rely on series of estimates of things you do know to estimate the things you don't know.
For this specific question, I have a much better idea of the number of households in the US, the proportions of households with cats, and maybe a less general sense of the proportion of households who currently have cats that are stray.

Also, what are people doing for questions that involve electron/proton radius? Values for this range from the femtometer (e-15) to sub-attometer (e-18 to e-19) lengths; is it just convention to use the classical electron radius (e-15)? If so, then if a proton radius is roughly defined at e-15 as well (which is also debated), then is an electron really over 10X denser than a proton?

[Name]

I think the idea is to rely on series of estimates of things you do know to estimate the things you don't know.
For this specific question, I have a much better idea of the number of households in the US, the proportions of households with cats, and maybe a less general sense of the proportion of households who currently have cats that are stray.

Also, what are people doing for questions that involve electron/proton radius? Values for this range from the femtometer (e-15) to sub-attometer (e-18 to e-19) lengths; is it just convention to use the classical electron radius (e-15)? If so, then if a proton radius is roughly defined at e-15 as well (which is also debated), then is an electron really over 10X denser than a proton?

I generally use the E-15 values for both because usually it's E-15 in the tests I've taken, and the eletron is not 10x denser because it's mass is around 1000x less. Discrepancies like this is basically what makes Fermi annoying. Like for licks to reach center of lollipop I've seen both 2 and 3 for the answers. For questions like ml of blood in a human, the estimate is 4.5-5.5 liters and you lose 2 points even though your answer is technically correct

While that method of estimating usually works, generally it's kinda off. (Like 1/3 families own cats so 3E7 families that own cats, and with that estimate 3E6 strays while the actual answer is 6E7 cats).