Science & Mathematics - 18 December 2007

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2007-12-18 13:16:45 · 2 answers · asked by Anonymous in Mathematics

Find the limit: lim x→1 (2- 5/(x-2)^2

2007-12-18 13:11:59 · 5 answers · asked by Anonymous in Mathematics

2007-12-18 13:09:28 · 1 answers · asked by Anonymous in Physics

If two dice are rolled, what is the probability of rolling a sum of 8 or a sum that is odd?

2007-12-18 13:07:11 · 7 answers · asked by calleighismygirl 1 in Mathematics

2007-12-18 13:06:54 · 13 answers · asked by arjay_575 1 in Astronomy & Space

So I'm writing a story my character's running from the bad guys + ends up hiding behind the counter type thingy that's holding all the elements in liquid form (long story as to how it got to that) and I need to know is there any chemical combination you could put in an empty water bottle type thing + you could drop a match in it + has a slow enough reaction time to add the lid + toss it then it would burst into flames thus exploding the bottle + basically making like a fire bomb? I/f so what is it called + what's some other information on it. please + thank you for the help.

2007-12-18 13:05:19 · 3 answers · asked by Mary 1 in Chemistry

Can i get a problem that i can do a project on
im in 9th grade

2007-12-18 13:04:32 · 1 answers · asked by Anonymous in Mathematics

find the exact values of sin 2u, cos2u, and tan 2u using the double-angle formulas:

Sec u = -(5/2)

pi/2 < u < pi

2007-12-18 13:03:22 · 1 answers · asked by Anonymous in Mathematics

2007-12-18 13:02:09 · 23 answers · asked by tomman1691 2 in Mathematics

a. Persons who are heterozygous for sickle-cell disease are also resistant to malaria.
b. About one in 10 African Americans is a carrier of sickle-cell disease.
c. Sickle-cell disease is common in tropical Africa.
d. Sickle-cell disease causes white blood cells to be sickle shaped.
e. All of the symptoms of sickle-cell disease result from the actions of just one allele.

2007-12-18 13:00:21 · 5 answers · asked by Anonymous in Biology

2007-12-18 13:00:02 · 2 answers · asked by jarheadbrat@sbcglobal.net 1 in Mathematics

Find the center of mass of the lamina which occupies the portion of the circle x^2 + y^2 <= 1, which is in the first quadrant and has density of rho(x,y)= x*y.

first, i calculated the mass: m= [0,1]int [0,1]int x*y dxdy
the mass i got was (1/4).
second i calculated x-bar (x coordinate):
4*[0,1]int[0,1]int x*x*y dxdy = x coordinate
x-coordinate = (4/6)=(2/3)
third, i calculated the y bar ( y coordinate):
4*[0,1]int[0,1]int y*x*y dxdy = y coordinate
y-coordinate = (4/6)=(2/3)

so the center of mass is (2/3,2/3). Is that correct? I just feel awkward seeing both coordinates equal. Is that what should happen in a circle or is it because the density function was just too simple and perfect?

2007-12-18 13:00:01 · 2 answers · asked by Kala J 3 in Mathematics

find the percent composition of a compound containing tin ahd chlorine if 18.35g of the compound contains 5.74g of tin

help me understand how you did it

2007-12-18 12:55:27 · 3 answers · asked by theskyzblu 2 in Chemistry

1. the expresion sin2x / 2cosx (sine 2 theta over 2 cosine theta) is equivlent too
a:sinx
b:cosx
c:tanx
d.cotx

2. which of the followiwng is the range of cos2x
a: -1 ≤ y ≤ 1
b: -2 ≤ y ≤ 2
c: -90 ≤ x ≤ 90
d: 0 ≤x ≤360

2007-12-18 12:53:13 · 1 answers · asked by Kelly S 1 in Mathematics

I got a chem final 2morrow And this is 1 of the concepts
How do You determine this?

For example
my study guide says
example:H2O.

Electronegativity O - Electronegativity H
3.44-2.20=1.24

The electronegativity between H and O is 1.24.

Therefore, H2O is polar covalent.

How do you know
O is 3.44 AND H is 2.20??

And another question.
Any good websites for polar & non polar bonds
like just a good site for explaining them well.

any Answer to these 2 questions.
THANKS

2007-12-18 12:50:41 · 7 answers · asked by Ace® 4 in Chemistry

are color-blind. What is the best explanation of this result?

a. The gene for color vision is incompletely dominant to the gene for sex determination.
b. The gene for color vision is linked to the X chromosome.
c. The gene for color vision is codominant with the gene for sex determination.
d. The gene for color vision is completely dominant to the gene for sex determination.
e. The gene for color vision is linked to the Y chromosome.

2007-12-18 12:50:36 · 2 answers · asked by ursportsguy 1 in Biology

find the exact value between 0 and 2pi:

(sin2x + cos 2x)^2 = 1

2007-12-18 12:49:22 · 5 answers · asked by Anonymous in Mathematics

I have to do an egg drop for Physics which I made and tested my design off a 3 story building. I made a cone and lid out off poster board and stuffed the inside with a bag of cotton balls and the egg in the middle(which survived). Now I have to explain why my egg survived and i don't know why because the only things I can think of is air resistance, elastic potential energy, and velocity, which none of the design uses. Can anyone tell me why it survived using physics?

2007-12-18 12:48:29 · 4 answers · asked by KiMkIm 2 in Physics

Maggie is running for class president. A poll revealed that 40% of her class made voted for her. 32% voted for her opponent. 7 voters are undecided. Maggie needs 50% of the vote to win. How many of the undecided votes does she need to win?

I think that I should make it into a whole, but sadly, I don't know how. Help?

2007-12-18 12:47:12 · 19 answers · asked by dqsmarty@sbcglobal.net 2 in Mathematics

I have the 10" itscope and love it,you made a great choice!
The views I get from Detroit Mi are wonderful. The DSC's work great in cold weather too.These apertures start to show you the colors of the stars and planets. The dbl. star catalog choices are awesome and to see the colors of these stars is a welcome change to the greenish colors of neb/galaxies. I align mine by racking in the focus w/ the 25mm until I see the out of focus rings and position the align. star in the center.I've also glued 2 sm. bubble levels from aco onto the base so I know if I'm on level ground, even if my warp factor is 0.5 it's still gets my object in the field of view at low power.Good luck with the new scope,if U have ?'s plz post them here and hope to hear how you like it, I may upgrade!

2007-12-18 12:45:42 · 1 answers · asked by Anonymous in Astronomy & Space

show steps

2007-12-18 12:45:27 · 4 answers · asked by Kelly S 1 in Mathematics

2007-12-18 12:44:17 · 7 answers · asked by Anonymous in Zoology

Im looking at equations, and I need to figure out what the precipitates that are formed in each of them..

One of which is:
Pb(NO3)2+Na2CO3 --> PbCO3+2NaNO3

Could I get some advise on how to find out what turns out to be the precipitate, and what is the (aq)?

2007-12-18 12:42:47 · 6 answers · asked by Anonymous in Chemistry

I am trying to figure out an example in my chemistry book. The question says: How many atoms are in 3.3 X 10^ -(negative)3 of gold. I know that the conversion factor is (.0033/197) X 6.022 X 10^23. What I cannot figure out is that the book has an answer of 1.0 X 10^20 atoms Au. However, when I type in these numbers on my calculator I get 1.0 X 10^19 atoms Au. Can someone explain why the answer is what my book says it is? Thank you!

2007-12-18 12:41:00 · 4 answers · asked by Steven M 3 in Chemistry

i know you factor by grouping but i got x^2(x-2)25(-x+2) can you go any further?

2007-12-18 12:40:36 · 7 answers · asked by Anonymous in Mathematics

i need to know what it looks like?

2007-12-18 12:37:26 · 3 answers · asked by emmajane d 1 in Mathematics

Many times, while I was out walking my dog at night (in South and Central Florida), I would come home to discover long welts across my arms or the side of my face.

Now, I did not feel anything sting or bite me while I was out, but by the time I got home, there was a burning/itching sensation and upon getting into the light, I would see the red, raised welts on my skin, anywhere from 2 to 6 inches long in a slightly curved line.

Washing them hurt and Cortisone helped a bit, but they still itched badly for days. It almost seems as if an insect dragged its stinger across my skin as it ran into me and then went on its way.

I was not in contact with any plants when these dragging stings occurred, I was walking down the middle of the road. The marks do not resemble mosquito bites at all (as I feel those immediately and they just leave one small bump on me).

Does anyone have any ideas what this mystery stinging insect could have been?

2007-12-18 12:36:24 · 5 answers · asked by Jylsamynne 5 in Zoology

2007-12-18 12:33:56 · 2 answers · asked by annette982006 2 in Botany

If there are nine ladies dancing and the probability of a dancing lady accepting an invitation to dance is .18, then what is the expected number of ladies you would have to ask before one accepts???

2007-12-18 12:33:22 · 4 answers · asked by Anonymous in Mathematics

2007-12-18 12:32:48 · 4 answers · asked by Anonymous in Other - Science