Science & Mathematics - 20 August 2007

C3H6 + H2 -- C3H8 Change in H = -124KJ

C3H8 + 5 O2 -- 3 CO2 + 4 H20 Change in H= -2222Kj

H2 + 1/2 O2 -- H20 Change in H = -286KJ

Use to determine the standard enthalpy of combustion of propene::

C3H6 + 9/2 O2 --3 CO2 + 3 H20

2007-08-20 08:58:09 · 1 answers · asked by philip c 1 in Chemistry

2007-08-20 08:57:36 · 22 answers · asked by Anonymous in Other - Science

Greetings,

Irrespective of some of the other previous questions about dark matter, I was wondering considering that WIMPs (Weakly Interactive Massive Particles) were soley suggested because they rectified some of the problems with how much the universe actually weighs because of calculations...SOOO...

My question is this: IF gravity is such a deciding factor for figuring out the total mass of the universe AND Newtonian Physics still describes how we calculate the total mass of the universe, THEN how, if at all, does Relativity effect the supposed idea of Dark Matter?

IOW, Someone explained to me that in order to calculate the total mass of the universe you had to use Newtonian Physics, I wanted to know if Modern Physics could describe it (the total mass of the universe) better?

2007-08-20 08:56:04 · 4 answers · asked by reverendlovejoy75 3 in Astronomy & Space

I'm an engineering student looking to design an aesthetically pleasing but durable light weight portable structure with tension fabric and a pvc pipe frame, but I'm not sure where to purchase architectural tension fabric. The structure needs to be large enough that it can comfortably house two individuals, but small enough that it could be erected by hand, so I'm thinking about 500 square feet of floor space and 10 to 12ft of verticle clearance would be ideal. Does anyone have a ballpark idea of how much something like that would cost? Any advice would be appreciated, and I am certainly open to suggestions for alternative materials if you feel these wouldn't be ideal for the application.

-Thanks
-James

2007-08-20 08:55:46 · 4 answers · asked by James333 1 in Engineering

If so, how should you build it? Would pole/piling be necessary? The specific property we're looking at is along a river, which is why the elevation is so low.

2007-08-20 08:51:40 · 3 answers · asked by Froda 2 in Geography

2007-08-20 08:42:36 · 4 answers · asked by Anonymous in Chemistry

yet its a pretty simple number 2 divide by 2 isnt it? try it on some people c how they do,
maybe im just asking people that arnt good at math

2007-08-20 08:41:42 · 11 answers · asked by Anonymous in Mathematics

Ok we all know that an electron has a negative charge..
but just for the sake of agument you were sitting on an electron and used a microscope what is it made of....?

2007-08-20 08:36:58 · 14 answers · asked by Anonymous in Physics

2007-08-20 08:33:03 · 4 answers · asked by Fred S 1 in Medicine

I am trying to solve a puzzle and I need to write equations for a horizontal and a vertical lines passing through (5, -4) that state the slope- how would I do that?

2007-08-20 08:32:48 · 4 answers · asked by Anonymous in Mathematics

When magnesium is burned in air the magnesium and oxygen combine to produce magnesium oxide. there are 15 grams of magnesium and 5 grams of oxygen. If all of magnesium and oxygen reacted. how many grams of magnesium oxide is produced?

2007-08-20 08:31:50 · 2 answers · asked by Anonymous in Chemistry

2007-08-20 08:26:50 · 9 answers · asked by angel 1 in Mathematics

I just read "the day after roswell" and from what colonel corso said in there it seems likely they all could have been results from an alien attack.

2007-08-20 08:25:59 · 11 answers · asked by wtf2008 1 in Astronomy & Space

2007-08-20 08:18:47 · 14 answers · asked by angel 1 in Mathematics

Can someone with a M.S from a non-accredited program of engineering become P.E?

2007-08-20 08:15:45 · 7 answers · asked by civic06 1 in Engineering

2007-08-20 08:14:42 · 4 answers · asked by Anonymous in Physics

Lungs

Liver

Spleen

None of the above

2007-08-20 08:11:33 · 10 answers · asked by Alyssa R 1 in Biology

did we ever go to the moon? did we have the technology back then?

2007-08-20 08:09:37 · 25 answers · asked by JC Z 1 in Astronomy & Space

Find an example of a real-life problem that involves exponents. State the problem. Explain how you would try to solve the problem. Use a problem that is different from everyone else's own

2007-08-20 08:09:30 · 2 answers · asked by shellyeph 1 in Mathematics

A student submits homework in which she writes:3 exponent is 2 x 3 exponent is 3 = 729 and(-3) exponent 2 = -9. What doyou think she did wrong, if anything? What would you advise her to do?

2007-08-20 08:09:05 · 2 answers · asked by shellyeph 1 in Mathematics

I was watching T2 the other day and I seen John Conner hack into a ATM machine using a Atari.(I know this is just a movie)But I was thinking with all of todays computers and gadgets do people do this?If somone was good with computers and knew how the machine worked they probly could pull it off.I know people do this all the time with slot and vending machines.

2007-08-20 08:04:51 · 5 answers · asked by Anonymous in Engineering

2007-08-20 08:02:09 · 5 answers · asked by matt r 1 in Mathematics

2007-08-20 08:01:29 · 2 answers · asked by lord_andys_new_id 1 in Engineering

I honestly think it was faked. To start, there are too many things wrong with the video tape like the shadows going the wrong direction and the flag waving and how you are able to see Armstrong coming down the side of the shuttle when the sun (which is the ONLY source of light) is on the other side of the shuttle. And really, what proof do we have that we DID land on the moon besides the astronauts testimonies and some moon rocks which have the same make up as earth rocks so they could have come from my backyard for all I know. And there was plenty of motive for us to fake it. When WWII ended the cold war started to see who was going to be the dominant force in the world, this started as an arms race in which both countries (US and USSR) amased enough nukes to blow the world up like 25 times over. Since this did not prove a winner of the cold war it became the Space Race to see who had the bigger balls. So basically whoever made it to the moon first was going to be the dominant force.

2007-08-20 08:00:50 · 18 answers · asked by lazyjbob 5 in Astronomy & Space

Esophagus

Stomach

Intestines

None of the above

2007-08-20 08:00:39 · 3 answers · asked by Alyssa R 1 in Biology

When magnesium and oxygen combine to produce magnesium oxid there are 3 grams of magnesium and 1 gram of oxygen of all of the magnesium amd oxygen reacted how many grams of magnesium and oxide are produced?

2007-08-20 07:59:46 · 2 answers · asked by Anonymous in Chemistry

This question was inspired by the one at http://answers.yahoo.com/question/index;_ylt=ApfyiAkLxa3nBMvRv5dBST3sy6IX?qid=20070816104652AAunj7P

For x >=0, let f(x) = lim [1/1^x ....+1/n^x - Integral (1 to oo) dt/t^x]. Then f(x) = lim [1/1^x ....+1/n^x - (n^(1-x) -1)/(1 -x)], if x<>1, and f(1) = lim [1/1 ....+1/n - ln(n)] , so that f(1) is the Euler/Mascheroni constant. Since the function u --> 1/u^x is strictly decreasing for x>0, the limit of the sequence always exist and f is well defined. For x >1, 1- x <0, both the series and the integral converge and we have f(x) =lim [1/1^x ....+1/n^x - 1/(x -1)] = Z(x) - 1/(x -1), where Z is the Riemann Zeta function. We know Z is analytic on the complex plane, so has derivatives of all orders on (1, oo). Therefore, , f has derivatives of all orders on this set and f'(x) = Z'(x) + 1/(x-1)^2. But I couldn't conclude if f is differentiable, or at least continuous, on [0,1].

2007-08-20 07:59:41 · 1 answers · asked by Steiner 7 in Mathematics

a) negative inside, positive ouside
b) neutral everywhere
c) positive inside, negative outside

2007-08-20 07:59:32 · 4 answers · asked by Alexander 6 in Physics

when we know that a lot of energy (as electromagnetic waves and particules) is travelling through space, is that not enough to fill in the mass deficit of the universe ?
we know of the duality wave particule or energy equal mass, why do we need dark matter ?

2007-08-20 07:58:20 · 6 answers · asked by Anonymous in Physics

+5- -6=?
-6 - +5=?

2007-08-20 07:52:05 · 6 answers · asked by Anonymous in Mathematics