/sci/ - Science & Math

What are the dangers of staying awake for over 48 hours straight?

Any long term effects on the brain?

http://dx.doi.org/10.1063/1.2349601

Halp!!!
need paper..

fuck you shitty library!

So /sci/ lately I have become increasingly interested with algorithms which describe social processes and functions. Most notably I have been really interested with algorithms which describe economic layouts, probability of loss and return, market trends, etc. I was wondering if anyone had a good place to further expand my knowledge such as a book/textbook. Also I would love to hear about some new algorithms which describe social aspects so throw ehm at me.

1. The problem statement, all variables and given/known data
While stationary on Earth you have a weight of 550N. When in an elevator that accelerates upward your weight temporarily becomes 590N. When descending, your weight temporarily becomes 510N. Find a) the acceleration you experience as the elevator moves up and b) the acceleration you experience as the elevator moves down.

2. Relevant equations
ΣF=m*a


3. The attempt at a solution
There are two forces acting on you in the elevator: the force due to gravity Fg, which acts downward, and the force of the floor on you Fn, which acts upward. According to Newton's 2nd law, the sum of these forces will equal m*a, so we can write
Fn - Fg = m*a
We know that Fg equals m*g, where g = 9.8m/s^2, so we can find the mass by dividing Fg by g, which yields about 56.1kg. Substituting in all of the known values and solving for a, we find that
for a)
a = (590−550)N/56.1kg = .713m/s^2
and for b)
a = (510−550)N/56.1kg = -.713m/s^2
The answer key and the others students got 10.5m/s^2 for (a) and 9.01m/s^2 for (b), which are the answers I got, plus g.
I'm pretty sure I'm the one who's wrong here, but I don't understand where I messed up. Help would be greatly appreciated.

Give me a Math problem which is hard but not unsolvable or a paradox and I will try to solve it.

Ok its simple, The game is played like this, you have to teach the poster above you a piece of Mathematics and the poster below you has to teach you. If you already know the statement or blip of math the poster above you has stated,first prove you know if by completing a few practice problems, then please reply "I know,re-roll." and the poster above has to repost a more complex part of Math. When you are the poster you should add the information which is necessary to know the Math and post a few practice problems. If you learn something new you must post "learned." The object of the game is to get the most people to learn. If you win you get a cookie and the satisfaction that you posted in a non-troll thread for the first time in /sci's/ history.

>inb4 Costanza,biology is not a science, and epic failure

I am about to go on a math study binge (no, not babby calculus). What preparations should I make?

>inb4 adderall

A list of advanced topics in mathematics and their respective ebooks.
http://hbpms.blogspot.com/

Bump

so there was this guy that needed to find the derivative of x^-2 using the limit definition...

Hello, /sci/borgs. I'm an undergraduate mathematics student who is just now crawling out of a very, very long depression. Needless to say, my grades and coursework suffered. But I changed that earlier this year, and now am confident I'll graduate soon. When I first went to college, I had doctoral aspirations. I gave up on that after flunking out of the first college and struggling in the (much less prestigious) second college. But now I feel energized again.

I want to receive a doctorate in mathematics.

But I've run across a problem: I thought that if I ever went to graduate school, I'd go back to the original college (UMBC). But now I've found that they only offer doctorates in applied mathematics and statistics. Apparently they're geared more toward government, industrial, or scientific (not math) research positions. So I need help and advice on good graduate schools for me. Here's what I'm working with (and I know, it's mostly shit, but I'm determined to get that fucking doctorate):
1) My GPA is 2.4. I have at most two more semesters to go. So it won't get that much better.
2) I'm 25. I don't know if that matters, but yeah.
3) I don't have any money saved right now, so I need a school with good financial aid.
4) I'm working with my professors on something I hope to soon have published. It's based on something I researched on my own, so I'm not just tagging my name onto a teacher's stuff.
5) I live in Pennsylvania right now.

Also, any tactics to get myself into graduate school. I already know that (hopefully) soon-to-be published article will look good, and I'm willing to even take graduate level courses without enrolling in the doctoral program (as a part-time student) to show that I can hold my own. So where do I look?

How/why did you personally choose or come to your undergad college major /sci/?
I'm a freshman that has never looked seriously at this matter until now, and I can't decide, since school up until now has apparently been extended babysitting.
Try to say more than "choose what you like." I'm doubting CS.

hey /sci/ I got one chance left or i'll get a B :( on this, i got it wrong twice

Use the formula for the Schwarzschild radius Rs to calculate the volume 4/3pi Rs^3 inside the event horizon of a black hole of mass M.

What does the mass of a black hole need to be in order for its mass divided by its volume to be equal to the density of water 1(g/m^3)?

The answer needs to be (answer) *Msun

How come Tabular Integration works?