The homework help thread

[Dishonru]

Need help with some homework, or maybe you have a small question that's not worthy of its own thread about a technical hobby? This thread has got you covered.

Please include the topic at hand, the problem or question, and any information you think is relevant. The posts below are provided as an example. Feel free to steal the format for your own posts.


Calculus 2, Chapter on integrating arc trig functions
Problem: Integral[3/(x^2-9) dx]

Attempting to integrate by using u-substitution didn't work.


I am supposed to write a haiku on baby seals. I'm not sure if I am doing it right. Here is what I have so far:

oh cute little seal
you walk and lumber about
club meets head seal meal

No question is too stupid. If you are having trouble with a question go ahead and post it. This thread is not limited to math or science related subjects. If you are having trouble wording part of your paper, or even coming up with a topic you are welcome to post here.

Homework Buddy List
Not everyone wants to post their problems in this topic. Maybe they are doing alright but want to discuss it with someone. The following people have volunteered to help out with certain topics. To contact them click their name and pick a method from their profile.

Dishonru (http://forums.irowiki.org/member.php?u=172) - Calculus, General Physics, Algebra/Geometry/Trigonometry
Digital Love (http://forums.irowiki.org/member.php?u=256) - French
Pete (http://forums.irowiki.org/member.php?u=74) - General Chemistry, Organic Chemistry, General Biology
Harb (http://forums.irowiki.org/member.php?u=701) - English
Hadas (http://forums.irowiki.org/member.php?u=19) - Economics
Bato (http://forums.irowiki.org/member.php?u=153) - French, calculus, Physics, Biology, Algebra, Trigonometry, Algorithmic[/url]
Heathyrre (http://forums.irowiki.org/member.php?u=118) - General Biology, Marine Biology, Oceanography
Bass (http://forums.irowiki.org/member.php?u=542) - Portuguese

[Pete]

I'm able to help with organic chemistry problems and chemistry in general. And general biology.

[Digital Love]

Digital Love - Can help with French homeworks.

[harb]

I can help w/ english

[Hadas]

I can help with economics assignments.

[Bato]

French, calculus, Physics, Biology, Algebra, Trigonometry, Algorithmic

[Heathyrre]

Stepping in for General Biology, Marine Biology, Oceanography.

[Bass]

Guess I won't be solicited at all, but I can help with portuguese.

[Dishonru]

Guess I won't be solicited at all, but I can help with portuguese.Is cala boca old slang or do portuguese immigrants butcher their own language?

[Cute Wittle Corgi]

I can help with English

[Harlequin]

I can lend a hand with English, Economics and anything CPA/MBA-related

[The Jesus]

I always spaced out during core classes but any Literature or Computer related subjects I'm your guy.

[Hadas]

I can lend a hand with English, Economics and anything CPA/MBA-related

Anything MBA-related or accounting and finance specifically?

[Swoff]

Swoff loves essays. English, History, even a subject I've never done - you can bet all your shekels I'd find something to improve.

[Harlequin]

Both =) I'm duel major getting my CPA and MBA in June.

[Hadas]

Both =) I'm duel major getting my CPA and MBA in June.

What is your MBA focusing on?

[Bass]

Is cala boca old slang or do portuguese immigrants butcher their own language?

Sorry for the late answer, I hadn't check the thread. Well, "cala a boca" is actually used as oftenly as "shut up". The way we talk it makes it sound like "cala boca", but the right form is "cala a boca", with "a" being the article equivalent to "the" on english.

[Isaboy]

wahaha i got it.

[Ichigo]

Quick, post basic code for a red black tree in c++ /go

[Navy]

Quick, post basic code for a red black tree in c++ /go

http://web.mit.edu/~emin/www/source_code/cpp_trees/index.html

[The Amazing Bob]

Here to help with English and Psychology.

[Ichigo]

alright now integrate a binary tree into that one and create a program for the umbala elemental stone breaking quest. :O!

purely inefficient but its for fun!

[Erethond]

I can help with Sociology studies. (This includes sociological research methods, and statistics.)

[Ko-No-Hana]

History is my strong suit along with Literature and English Composition.

[Kenny Loggins]

History, English, Digital Media Arts.

lol @ anyone giving me any question about DMA.

[odin]

Very Strong at Math & Science

[Wilton]

Good at social science theory mechanisms.

[Memeroyx]

Political science, government, or history =D

[nneg]

political science, philosophy or any other useless major and FSL

[CrimsonBlitz]

Subject: Political Science

Problem:
Knowing the current presidential selection process, what are some things you could improve on within the system. (i.e. presidential nominations, electoral college, nominations of less rich white men, etc) Create a small list of the biggest problems plaguing the system.

I'm looking for some ideas on what to put down... and perhaps some more eloquent phrases.

[CrimsonBlitz]

the thread died?? :(

[Ichigo]

the thread died?? :(

They wan' a dime that's top of da line.

Unless this thread is a smoking hot female tutor with measurements close to a perfect 10 ratio, lack of interest will ensue.

[Ko-No-Hana]

Does anyone speak Mandarin? Or know of places where I can find help on speaking/pronouncing chinese? Sob sob

[Acolyte]

Subject: Political Science

Problem:
Knowing the current presidential selection process, what are some things you could improve on within the system. (i.e. presidential nominations, electoral college, nominations of less rich white men, etc) Create a small list of the biggest problems plaguing the system.

I'm looking for some ideas on what to put down... and perhaps some more eloquent phrases.

To answer your question:

One of the biggest problems I can think of is no popular sovereignty when electing the U.S. president. Like in Gore Vs. Bush, the

majority of Americans wanted Gore to win but he lost due to being short in electoral college votes. Many Americans believe their

votes count when soon realize their votes do not when determining the president. But there are some states that doesn't use a

winner-take-all system. To help promote a more direct democracie, some states are following the same path as Maine and

Nebraska. In the upcoming election, california is voting if they should use a system like Nebraska and Maine. This will create a huge

change in running for the electoral college vote because California is a whopping 55 electoral votes and stats shows from last

presidential election was 22 electoral votes for the republics and 33 votes for the democratic. If this was to pass by California, we

will be seeing more Republicans campaigning for California Electoral Votes. This will allows Californians to have a direct vote in their

saying for who should be president.

Please ignore my grammar mistakes. This is what I thought of when thinking about your question.

Also, if any1 needs help with General Botany, let me know. I'll be glad to help.

[a]

Does anyone speak Mandarin? Or know of places where I can find help on speaking/pronouncing chinese? Sob sob

i can do canto, mandarin sucks >: o

[Fallenwings]

I speak pretty fluent mandarin, however I learned it the "traditional" way with Chinese characters instead of the Romanized pin-yin stuff they teach in American schools/colleges. I only was exposed to that vaguely.

[Cute Wittle Corgi]

is anyone here good at autocad

[Ichigo]

is anyone here good at autocad
What is thy question? Should probably add me to the AutoCAD help subject I guess. Usually most questions are based on scale. The command ltscale would tell you if you're working on a 1/8 scale (96.00 on cmd screen) or 1/4 scale (48.00 on cmd screen).

[Iluvatar]

I can help with Portuguese only I guess =\

[einfarbig]

I suppose that very few people in here actually learn German, but if there's any chance I could help with that, feel free to post your problem here.

[Cute Wittle Corgi]

is anyone good at statistics

[The Jesus]

Yeah but there's a 9 in 10 chance I'll be wrong.

[CrimsonBlitz]

thanks for the help, a week late... but much appreciated.

[Shaohuan]

English(grammar/composition/lit), French, basic Japanese, general chem, general biology, human anatomy and physiology, and music

It seems kinda a lot, but the English half I was drilled on (literally, we did drills everyday) in elementary-8th grade, French/JP I've studied for years, and I've played piano for 15 yrs now. Otherwise it's all stuff I'm learning in college. D:

Edit: Oh, and US history. My dad was a history freak and what not.. Took me to all the historical landmarks in eastern US, watched History channel with me, and otherwise taught me history in the car. ):

[-Mck-]

I can help with Spanish and English :o

[Awake]

I can help with Danish, hah. I've never met another Dane on this forum but should anyone from the tiny country of 5,5mil people have language issues I'd help out.
I also have some knowledge of health, nutrition and psychology.

[einfarbig]

Hey. My name is Peter and I am an apple pie. Yeah, I know what you're thinking right now.
But Peter is not such a bad name after all. I'm going to tell you a story about me and my
career.
First, being an apple pie is not quite the easy life everyone else thinks it is.
You don't start being that cool cake everybody wants to have at his fancy birthday party
or even wedding! When I was a handmade cake back in the days, I only got to see old grannys
and their families every second sunday or so. However, having those grandchildren
picking the fresh fruits out of you is great, look at their satisfied faces!
When I grew up I became more and more popular. "You heard of that awesome apple pie
you can get at that little house down the street?" Sure, I did!
Every now and then I got to visit a birthday party, which was a great experience but
a little tiring after all. My fresh fruits just were not made for long trips and microwaves.
I had to say goodbye to them and welcomed (?) my new friends, they said they've been
having a hard time traveling from Europe all the way to the US. I felt sorry for them
as their skins looked not half as bright and shiny as the skins of their forerunners.
Those people in Europe must be cruel. And they don't seem to eat much apple pie, which
makes them even worse, if you ask me.
But with my new friends I had even more appointments to meet. Birthdays with everyone
wearing a suit and noone actually celebrating, strange, isn't it? But seriously,
what would you expect from parents who only invite old people and who call their
little boy "CNN". Weddings with everyone dressed in black - that were some strange
celebrations, people cried and cried and I didn't really know whether it was my fault.
I figured that chosing that factory made sugar might not have been my brightest moment
but hey - that's no need to start crying, come on! I am still tasty!
For the first time I wished back those old days. My apples, dear, I could see them growing
on the trees in our garden. Now they talk about dutch conservatorys.
I don't even know where that "dutch"-boy lives. But they say he makes them grow much faster.
I also missed those sunday afternoons with grandma and her people, their satisfaction when
they first saw me and even their satisfaction when I was finally gone.
Those suit-wearing people seem not to care for me too much. They don't pay attention, they
talk about that "bill" guy and how they want to pay him. Bill must sell a lot of things,
he's on everybodys lips.
Now that I've seen billions of places and made friends with blueberry I noticed how he
got more and more popular. We travel together almost every time, whereas I was quite a
lonely apple pie back in the days. But I had to watch out for him not to overtake me,
so I decided to put more and more fake apples into my belly.
They don't really taste and I think they don't want to be here as well, but they do their
job. One of them told me he was about to become a blueberry but preferred being an apple.
He didn't look too healthy but being an apple is far better than being a blueberry.
And now, would you excuse me, please? Me and seventy nine of my finest buddys are leaving
now. We have to meet that guy who turns 50 today, what was his name again? I think
it was something along the lines of "American Airlines".
----

My english homework. I'm not good with every/any/body/one.. please correct this little text asap!
Thank you guys.

[Shaohuan]

Hey. My name is Peter, and I am an apple pie. Yeah, I know what you're thinking right now.
But Peter is not such a bad name after all. I'm going to tell you a story about me and my
career.

First, being an apple pie is not quite the easy life everyone else thinks it is.
You don't start being that cool cake everybody wants to have at his fancy birthday party
or even wedding! When I was a handmade cake back in the days, I only got to see old grannys
and their families every second sunday or so. However, having those grandchildren
picking the fresh fruits out of you is great--look at their satisfied faces!
When I grew up, I became more and more popular.

"You heard of that awesome apple pie
you can get at that little house down the street?" Sure, I did!
Every now and then I got to visit a birthday party, which was a great experience but
a little tiring after all. My fresh fruits just were not made for long trips and microwaves.
I had to say goodbye to them and welcomed (?) my new friends.

They said they've been
having a hard time traveling from Europe all the way to the US. I felt sorry for them
as their skins looked not half as bright and shiny as the skins of their forerunners.
Those people in Europe must be cruel. And they don't seem to eat much apple pie, which
makes them even worse, if you ask me.

But, with my new friends, I had even more appointments to meet. Birthdays with everyone
wearing a suit and no one actually celebrating, strange, isn't it? But, seriously,
what would you expect from parents who only invite old people and call their
little boy "CNN"? Weddings with everyone dressed in black--those (wrong demonstrative pronoun was used here) were some strange
celebrations. People cried and cried, and I didn't really know whether it was my fault.
I figured that choosing that factory made sugar might not have been my brightest moment,
but, hey: that's no need to start crying, come on! I am still tasty!

For the first time, I wished back those old days. My apples, dear, I could see them growing
on the trees in our garden. Now they talk about dutch conservatories.
I don't even know where that "dutch-boy" lives. But they say he makes them grow much faster.
I also missed those Sunday afternoons with grandma and her people: their satisfaction when
they first saw me, and even their satisfaction when I was finally gone.

Those suit-wearing people seem not to care for me too much. They don't pay attention, they
talk about that "bill" guy and how they want to pay him. Bill must sell a lot of things--
he's on everybodys lips.

Now that I've seen billions of places and made friends with blueberry, I noticed how he
became more and more popular. We travel together almost every time, whereas I was quite a
lonely apple pie back in the days. But I had to watch out for him not to overtake me,
so I decided to put more and more fake apples into my belly.
They don't really taste(like what?), and I think they don't want to be here as well, but they do their
job(run-on). One of them told me he was about to become a blueberry but preferred being an apple.
He didn't look too healthy, but being an apple is far better than being a blueberry.

And, now, would you excuse me, please? Me and seventy-nine of my finest buddys are leaving
now(REDUNDANT). We have to meet that guy who turns 50 today. What was his name again? I think
it was something along the lines of "American Airlines".


Not bad, but I'm a fucking grammar nazi. Bolded everything that should be changed cept for stuff like spaces in "no one".. Some spelling errors or typos.. Numbers like "seventy-nine" are usually hyphenated by most grammar rules.

Please, for the love of God, learn when to use commas, semi-colons, and colons. No one knows how to use these anymore, and it's so fucking annoying. Any unnecessary information is set off by commas(appositives). When following a flow of logic, a lot of your phrases technically become unnecessary information, thus all the commas being added. Also, any time you have a phrase that could stand alone (i.e. there's a subject and a verb for that specific sentence), it needs to be set off. If it's connected through conjuction words like and, use a comma. Semi-colons and colons are used without conjuction words. "--" is used like a semicolon in an informal writing.

edit: Went through to mark where a new paragraph should begin because of subject change. I notice you use "but" too much. Try for alternatives. (And I don't just mean replacing them with howevers.) Also, a few other sentences were rather redundant. Reword or break them up. I didn't cos I don't want to screw up what your meanings/whatever you wanna call it. I put some comments around the ones I saw immediately, as well as some other comments.

edit2: "-" should be typed --, because in word, it autoreformats to the exact symbol (forgot the name), but it's like a long -. This is late but it might help other ppl with their papers.

Yes, I'm worse than your college English prof. :]

[Dishonru]

But Peter is not such a bad name after all. something must change

Are you allowed to cross out words? I'd remove the but. In order to use but like there a comma should be some where, but there is no appropriate place for a comma (after name would be awkward, after but would be silly because the previous sentence doesn't set this sentence up at all). If you have a set of rules to follow then use those, but other wise I'd look in to removing the word but.

[Shaohuan]

something must change

Are you allowed to cross out words? I'd remove the but. In order to use but like there a comma should be some where, but there is no appropriate place for a comma (after name would be awkward, after but would be silly because the previous sentence doesn't set this sentence up at all). If you have a set of rules to follow then use those, but other wise I'd look in to removing the word but.

As a rule of thumb, my 8th grade teacher took off a point every time we started a sentence with but. I follow it myself, but I gave up on changing ppl's paper's for it since I found English profs in college didn't give a shit.

[einfarbig]

Thank you very much for your input!

@Dish

If you would cross that "but" out, it would sound like the reader (or, [is that a right comma?] the people the pie is referring to..) thinks that Peter is not such a bad name, but, (comma?) the humor is that they actually do.

@Shaohuan

For whatever reason, punctuation is not taught in German schools until the topmost grade. This is because your punctuation appears to be random compared to our language (and I suppose this is mutual). However, in the final exam you will get assraped if you put a wrong comma.
I do not get the "-" and "--" thing, though. Could you tell me what exactly you mean with that?
Thanks again!

[Shaohuan]

Oh. Technically, a hyphen in a sentence should be long. Instead of "-" it's "--". In Microsoft Word, it automatically reformats "--" to the longer, single line you see in most English articles/what not.

Commas are a bit easier than they make them out to be. Unnecessary phrases (like: I have a sister, Ann. This would be saying you have ONE sister, thus not necessary to discern who it is.) are set off my commas. When applying them to phrases like, "When I was young, (main sentence here)," it's harder to explain if you didn't get taught what was an fragment versus phrases which don't require it since an early age.

That's not bad at all, really. I see college students with worse grammar, honestly.

[einfarbig]

Problem is, I'm a lazy fuck. In my language, I publish stuff and I even get paid for doing nothing but writing a text (18 years old). If you asked me to tell you something about German grammar, I would, most likely, die in agony, yet I hate to see people misspelling a word or messing up punctuation. I decided to change that and I thought it would be a good idea to learn the grammar of your language as well.
Learning by speaking is a no go for me as I am struggling with that darn (!!!) "th". Seriously, everyone in Germany seems to be a master of applying a "th" to their tongue (is it tongue or tongues here?) but I fail miserably. I don't know why. I am that kind of guy who refuses to talk on Xbox Live because I fear that someone shouts "Listen to that jerk messing up a simple th!" instantly. :D.

[Shaohuan]

Shouldn't worry about it. Plenty of ppl in the US can't even speak English properly.

I believe it's their tongues. Their tongue would imply all of them have one tongue they all share.

[orangejuice]

Does anyone speak Spanish as their primary language? I'm writing a paper in Spanish and later this weekend I need someone to read it over for grammar mistakes.

[einfarbig]

Hey,

could anyone provide me with a link to a site that explains stylistic devices such as parallelism, chiasm, metaphor with examples (!!), please?

I'll have to analyze a speech tomorrow, going to be a US president, either an inaugural address or a nomination speech.

[Schlafly]

I'm doing an advanced physics course even though I am terrible at math and physics and I need this completed by tomorrow so if anyone could help it'd be great.

A 0.046kg ball is laying on the ground. If the rest energy of the ball were used to operate a 75-watt lightbulb, how long would the bulb remain lit? The bulb uses 75 joules of energy/second.

Thanks if anyone sees this and can tell me how to do it. The only thing I can think of to use is PE=m x a x height but I don't have a height so I can't figure out the rest energy...

[Shaohuan]

I remember from my physics, that if the ball is at the lowest point, it's PE=0 (height = 0)

[Ysu]

If this is basic quantum physics, then rest energy is E=mc^2 but I remember only using it for particles. For Newtonian physics, I'd probably go with Shao's response.

[Shaohuan]

If this is basic quantum physics, then rest energy is E=mc^2 but I remember only using it for particles. For Newtonian physics, I'd probably go with Shao's response.

Yeah, only used E=mc^2 with particles in quantum.. I'm guessing Newtonian as well

[Saladin]

You are carrying out a fractional distillation of methanol-water at atmospheric pressure. The mixture begins to boil yet your thermometer reads 25 C. Why?

Why would it boil at room temperature at atmospheric pressure? Before anyone suggests it, yes, methanol's boiling point is higher than 25 C and obviously water's is, too.

[Gaignun]

E = mc^2 does not come from quantum mechanics. The formula results from Einstein's theory of special relativity, and it technically applies to anything. Seeing that the equation mentioned rest energy, which is a concept of special relativity, and provided information of the ball's mass, the formula is the one that should be used. Potential energy is meaningless because its zero-point is completely arbitrary. Once the nature of the problem is classified, the mathematics are very basic. Only two equations need to be invoked, one of which has already been discussed:

E = mc^2
P = E/t

Solve for time, t.

t = E/P
t = mc^2/P

At any rate, I suppose the answer comes too late. =[

[Ysu]

Normally you go more in-depth about relativity for getting started in a quantum physic course so I just said that in general. Eventually you build up to the slightly more complicated stuff and comparing the quantum mechanic cases to the classical cases (which is the part where you said it applies to everything). Didn't know what physics course he was taking :(

Not a big fan of physics though so Quantum I was the last required course I had to take :D I'm more towards the chemical engineering side. :P

[Ysu]

You are carrying out a fractional distillation of methanol-water at atmospheric pressure. The mixture begins to boil yet your thermometer reads 25 C. Why?

Why would it boil at room temperature at atmospheric pressure? Before anyone suggests it, yes, methanol's boiling point is higher than 25 C and obviously water's is, too.
I think I remember this somewhat. I believe it involved something with formation of azeotropes which affects the boiling point of the methanol-water mixture. There are two types of azeotropes (well in a starting orgo lab anyway). In your case, the azeotrope's boiling point is lower than both methanol and water. I'm really bad at explaining this so maybe look it up on Wikipedia.

I remember having to include this as a possible source of error when writing your discussion (if the experiment was based on fractional distillation) in the orgo lab

[Saladin]

I figured it out~ It was really stupid too -_-; The thermometer is reading the room temperature because although the solution has started boiling, the vapors have not reached the thermometer yet, so it is not registering the higher temperature of the boiling solution.

[Tam]

Yeah make sure you wrap that crap w/ foil or glass wool or something!
Keep the vapor in :)

[Soku]

Let f(x) = cos(x)/x

Find area enclosed by the graph of f and the x-axis.

Limits of Integration: pie < x < 2pie (< = greater than or equal to)

Question is if there is a way to find the anti derivative by hand or is math 9 the only way to do this?

[Gaignun]

You can find the antiderivative by hand, although you will be unable to find an exact solution. You need to do a Taylor series expansion of cos(x)/x and integrate term by term.

Taylor series expansion:

cos(x) = 1 - x^2/2! + x^4/4! - x^6/6! + x^8/8! -+ ...

cos(x)/x = 1/x - x/2! + x^3/4! - x^5/6! + x^7/8! -+ ...

cos(x)/x is readily integrable in this form.

Int( cos(x)/x ) = ln|x| - x^2/(2!*2) + x^4/(4!*4) -+ ...

Clearly, the best method to solve the definite integral is to use a computer, but if you wish to do it by hand, simply sum enough terms until you have a desirable accuracy.

[kunn]

Reviving this thread since i'm running out of luck on this summative =_=

i've been looking for several statistics, for my data management summative over the last few weeks.
But due to sheer luck, i picked a topic that has little to no info on it in a wide span of time (cyber crimes and data breaches)
Took me awhile to even find the number of data breaches from 1990-2003.

If anyone knows where some of these statistics are over the net, since i only have 3 days till the teacher goes over it and suggest her changes and 5 days till i have to present this infront of my classmates

searched google for about 1 week and got a few helpful stats, searched sites like stats can and etc
looking for:
- average cost of damages of a computer breach per year between 1990-2007

-Total costs of damages of a computer breach per year between 1990-2007

-cost of maintaining a network 1990-2007

-anything else that might be helpful and relates to or could effect data breaches and cyber crimes

-graphs are helpful but i still need to turn the graphs back into data, so i can recreate the graphs in fathom

I wish i picked something like hockey or baseball now =_=

[Sora`]

You can try looking at http://www.sans.org/ for research by going into the reading room. I actually don't know where any specifics are on the site since I just read the newsletter that gives a lot of articles about that sort of thing

Could also browse through http://www.sans.edu/ in the resources section for some articles there

[kunn]

thanks but couldnt find any of the material i was looking for at the time from those sites.

Decided to take a new angle, as in potential targets aka number of people online and number of internet sites, got some info but not much from that site

still cant find the average or total damages for internet crimes per years

Edit: i decided to keep looking through that site and eventually i found a really helpful piece of data
total cost of damages in 105 companies due to cyber crimes, over the years.

closest thing i'll ever find to what i was looking for

thanks

[Cute Wittle Corgi]

Easy question for you all.

So we're supposed to convert D-M-S (Degrees/Minutes/Seconds) to Decimal Degrees (which I have done)

An example is as follows:

140 deg 56' 56" which converts to 140 + (56/60) + (56/3600) and we arrive at the final answer of 140.9489 when I round.

My question is. How would I do a check to make sure I got this answer correct?

[Gaignun]

Does punching it into a calculator count?

[Shaohuan]

Does punching it into a calculator count?

I know when I had to do this, the calculator did not give us the same answer that we got when using our teacher's way. Yes, he did it on purpose so we couldn't simply do it in our calculator.

[Cute Wittle Corgi]

Does punching it into a calculator count?

no :(

[CH Falconner]

Hmm. Can help in Portuguese, Spanish, A bit of Italy, English, A bit of japanese, Brazilian and some European history... I think just it so. I'm 14, don't expect more.

[Resplendent]

Anyone taking an econ class/with econ experience: I'm totally at a loss to be able to graph Supply/Demand curves as my brain is wired to graph X on the horizontal axis and Y on the vertical. Having them switched is like oh god wtf :( Any tips for being able to do so?

Edit: I guess the easiest way for me is just to translate the equations into points and graph those...

[Cute Wittle Corgi]

okay so I got 200/200 marks by doing the following with that problem

for example 94.9889 I had to do (.9889 * 60) making this my minutes
then whatever the decimal was of .9889 * 60) I do it again and multiply it by 60, which gives me my seconds

so I go from 94.9889 DD's back to 94 deg 56' 56" and I got it right

I was only 2/25 who got perfect marks on this lab 8)

I will probably ask for help on simple checks again in the coming future though :(

[Dishonru]

Anyone taking an econ class/with econ experience: I'm totally at a loss to be able to graph Supply/Demand curves as my brain is wired to graph X on the horizontal axis and Y on the vertical. Having them switched is like oh god wtf :( Any tips for being able to do so?

Edit: I guess the easiest way for me is just to translate the equations into points and graph those...S/D curves are only confusing until you realize what they show. It's two graphs using the same independant variable to get different dependant results. I think I said it right, but I may have gotten things backwards. All I mean is that both of them rely on price, and are at the same price point. Price is like X, and after the demand or supply function for that graph is applied you get the number of people willing to buy it (Y). It could be thought of as

f($1) = s
g($1) = d

[Sparkous]

I have a physice question....copied and pasted it. I tried f & e/f (can select multiple answers...not sure if your supposed to though) and those were wrong. Now i have one try left /hmm...

A glob of slime is launched or dropped from the edge of a cliff. Which of the graphs in the figure below could be possibly show how the kinetic energy of the glob changes during the fight?

(a) (b) (c) (d) (e) (f) (g) (h)

http://www.webassign.net/hrw8/7-23.gif

[meko]

PICK F! PICK F!!!

[Ko-No-Hana]

I have a physice question....copied and pasted it. I tried f & e/f (can select multiple answers...not sure if your supposed to though) and those were wrong. Now i have one try left /hmm...

A glob of slime is launched or dropped from the edge of a cliff. Which of the graphs in the figure below could be possibly show how the kinetic energy of the glob changes during the fight?

(a) (b) (c) (d) (e) (f) (g) (h)

http://www.webassign.net/hrw8/7-23.gif


And this is why I'm a history major...

I have a big movie presentation to do for my current world history class. So basically anything from 1945-present day, I need a war movie, or movie involving Historical Events to do a project on.

Examples my prof gave us were: Platoon, Saving Private Ryan, Sophie's Choice, Shindler's List, etc etc. I haven't seen a handful of movie's on the 100 choices he picked out, but I want to know whats some of your favorites and why. This way I can do something I normally wouldn't chose, and maybe get some extra knowledge from it. =P (Foreign movies included)

[Bato]

Shame it doesn't include ww1, I would have said Paths of Glory.

[kunn]

there used to be this program on another site, which would go over your formal writing (essays and shit) and punctuate all the little details that a english prof would note or mark you down on

anyone have the link to this site =(?

[Acolyte]

I have a physice question....copied and pasted it. I tried f & e/f (can select multiple answers...not sure if your supposed to though) and those were wrong. Now i have one try left /hmm...

A glob of slime is launched or dropped from the edge of a cliff. Which of the graphs in the figure below could be possibly show how the kinetic energy of the glob changes during the fight?

(a) (b) (c) (d) (e) (f) (g) (h)

http://www.webassign.net/hrw8/7-23.gif

I can probably get an idea from this if you define to me what is kinetic energy.

[Gaignun]

A glob of slime is launched or dropped from the edge of a cliff. Which of the graphs in the figure below could be possibly show how the kinetic energy of the glob changes during the fight?

If the question is posed that way, then I could perceive the scenarios e through g.

e: Tossing slime vertically upward. Kinetic energy reaches zero at the top of the flight.

f: Dropping the slime from rest.

g: Tossing slime upward, but at an angle so that, at the apex of its trajectory, the slime still possesses lateral kinetic energy.

h is tempting, but wrong. Kinetic energy is proportional to ( gt + y'(0) )^2, so if y'(0) makes the kinetic energy nonzero, y'(0) also makes the derivative of kinetic energy nonzero. The derivative of kinetic energy can only be zero at t = 0 if the slime is being dropped from rest. Option h says that the slime has kinetic energy while being dropped from rest, which is a contradiction.

[Shaohuan]

..being launched and dropped is 2 different things too, isn't it?

Being launched adds the acceleration it receives from the mechanism, where being dropped only has the acceleration from gravity?

Or does that not affect KE? Idr anymore

edit: KE=.5m(v^2) so the way it's acclerating should have some affect on KE no <_<?

[Dishonru]

h is tempting, but wrong. Kinetic energy is proportional to ( gt + y'(0) )^2, so if y'(0) makes the kinetic energy nonzero, y'(0) also makes the derivative of kinetic energy nonzero. The derivative of kinetic energy can only be zero at t = 0 if the slime is being dropped from rest. Option h says that the slime has kinetic energy while being dropped from rest, which is a contradiction.
h is correct because it says "launched" and it is possible to launch something downward, but that is a pretty shitty way to word a question and really vague

I guess h could be wrong because if it starts with an initial velocity it won't accelerate slowly through the air like h shows. It's pretty awkward overall, and I think the prof is just looking to make sure you don't pick anything from the top row.

[Teon]

I'm going to ask it here hoping maybe there's a genius among us. I'm currently studying for an almost impossible fluid dynamic test (I'm currently a senior in biochemical engineering) with this hardcore professor (MIT guy /sob). This question got me stump:

A long circular cylinder of radius R1 rotates with an angular velocity W IN an infinite fluid. Determine the velocity profile.

I know it's a bit late to ask, but does anyone know? If you don't know the Navier-Stoke Equation don't bother :confused:


Yes, yes, I know...why bother asking in an RO forum..well, I tried? I'm also googling for an answer so yea /swt

Ok, I did it and I got the Veolcity in the Angular direction is R1^2W/R
I'm not sure whether is right....Damn Fluid homeworks and their infinite amount of assumptions:mad:

[Gaignun]

h is correct because it says "launched" and it is possible to launch something downward, but that is a pretty shitty way to word a question and really vague

I guess h could be wrong because if it starts with an initial velocity it won't accelerate slowly through the air like h shows. It's pretty awkward overall, and I think the prof is just looking to make sure you don't pick anything from the top row.
Even if the graph did contain a discontinuity at t = 0s, I still couldn't see how its rate of change of kinetic energy could start at zero from a mathematical perspective. Correct me if I'm wrong, but all launching would do is change the slime's momentum, as expected of an impulse. There can be no momentum without velocity, and velocity would cause the first derivative of kinetic energy to be nonzero. The only way I can validate h in my mind is by supposing that the graph was velocity versus time instead.

h still could be correct. I often do not trust my own reasoning. I concur that the question is, indeed, poorly worded.

[Teon]

From those graphs, f is right if it were dropped initially without any velocity, but since you said it was wrong /hmm.

[Ysu]

I'm going to ask it here hoping maybe there's a genius among us. I'm currently studying for an almost impossible fluid dynamic test (I'm currently a senior in biochemical engineering) with this hardcore professor (MIT guy /sob).

Damn Fluid homeworks and their infinite amount of assumptions:mad:
Hey, another Chem Eng major! I took that course last semester and I must agree that homework does suck in class. Only 4 problems per homework set and each problem is around 2 pages long average. I'm a junior in chemical engineering at UIUC. I hear the senior project designs are lovely.. as in the simulator does not work most of the time.

Did you take any class that is called something like "Chemical Reaction Engineering"? Our homework is leaning towards using Polymath to solve multiple ordinary differential equations. 2 problems and each one takes a good 1.5-2hr :(

[Teon]

Wow another Chemical Engneering major playing RO!?! I never thought that'll ever happened (Our colleagues will probably ridicule us for not solving problems all day and night if they ever find out:().
Yes, it is a requirement over here as well to take Reaction Engineering (It isn't hard at all compare to Fluid! The homeworks are long for sure, but not hard:)) I'm actually registering and taking a Graduate level course in Reaction Engineering next quarter after this (That or Enzyme Engineering)

We don't use Polymath (the Laboratory lost the license, so we just use Mathlab or Mathematica). Most ODEs are easily done by hand so I actually do it like that.

I'm under the U.C. system and my area is biochemical engineering so it is a requirement to take several junior and senior courses in biochemistry too. I'm not sure about my senior project though I know is going to be tough.


I'm too far in the biochemical engineering program to change my major, but sometime I wish I went pre-med instead. :(

[Ko-No-Hana]

Shame it doesn't include ww1, I would have said Paths of Glory.

Sadly, current history is considered 1945-present or 1877-present. This particular class is focusing on 1945+. I decided to go with 'Black Hawk Down', because from what I know, its the most accurate war film made by Hollywood.

It's also one of my favorites.

[Dispel]

I'm too far in the biochemical engineering program to change my major, but sometime I wish I went pre-med instead. :(

Just curious: Why?

[Old Mandrill]

I can help with art and creative writing :)

[xaerael]

wow, never noticed this thread. great idea.

i can help with: (time depending ^^;; )

optics (physical, not biological, although i have limited knowledge there too) currently hold an SMC(tech) in optical technology and 7 years of practical experience.

photography (mainly nocturnal/low light/conceptual) currently finishing final year of a BA(hons) degree in Photographic design, and hold a distiction diploma in foundation art.

PM me!

[Teon]

Just curious: Why?[/COLOR]

Money;)! And also being a pre-med is so much easier. As a biochemical engineering major, I've had weeks without any sleep even when there's no tests:(

In fact, most of the biochemical engineers I know are going to medical school right after graduation. Who wants to be an engineer when the work is hard and the pay is low?

Edit: The only reason I went into biochemical engineering in the first place is because I love chemistry/physics. Those majors make absolutely nothing even with a phD so I went into the engineering discipline:(.

[Teon]

Reviving old thread. I have a new question I doubt anyone cant answer but I'll tried it anyway! (Maybe Ysu can answer it or some physics major studying classical fluid mechanics :)).

A 1/2 in. plastic sphere (density= 38 lbm/ft^3) is released from the bottom of a deep lake. What is the terminal velocity?

That was tricky! Ok I figure it out (along with my colleague :D):
1. Start with Stokes Law (Dealing with Drag Force for sphere moving through liquids)
2. When the Sphere reach terminal velocity, the Graviational Force and the Drag Force (both forces opposing the sphere's movement through the infinite lake) is EQUAL to the the buoyancy Force!
3. The Lake is infinite

Assuming the Lake is compose of sea water, getting the viscosity values and the density values for temperature of 70 degrees Fahrenheit, final value is 117 ft/s :)

[ChrisTurk]

N> computer science 2 tutor /gg

[Teon]

Unless your classes uses Mathmatica or Matlabs, I can't help you there. I took C++ 4 years ago, and I don't think they still uses that program do they? (I was told by that professor Java was going to be the next thing :()