Science & Mathematics - 19 January 2007

Take any 3-digit number, and repeat it to form a 6-digit number. For example, choose 549 and repeat it to form 549549. Why are these 6-digit numbers always evenly divisible by 13?

2007-01-19 12:59:16 · 9 answers · asked by godfatherbuff 1 in Mathematics

sweet. sour. a certain type?

2007-01-19 12:57:41 · 9 answers · asked by Cyn A 2 in Biology

3x >or = to 2x - 4

7(x - 3) > 5x - 14

2007-01-19 12:57:03 · 3 answers · asked by robpurpleblazekamp 2 in Mathematics

A measurement of its thermal capacity inside a container having the constant volume 100 liters shows that under these conditions ,the thermal capacity is constant and equal to 0.1 cal./deg.Express the energy and the enthropy of the system as a function of T and V.

2007-01-19 12:55:07 · 1 answers · asked by joy 1 in Physics

what hardness, and whay other ways can i identify it?

i have a large carved pendant, a large ankh, at least one pound.......it was $4,000.00

2007-01-19 12:51:27 · 3 answers · asked by carolthec4 1 in Earth Sciences & Geology

(assume a constant specific heat =1cal./gm.deg.)

2007-01-19 12:48:03 · 1 answers · asked by joy 1 in Physics

electricity for home resident living

2007-01-19 12:46:32 · 1 answers · asked by Anonymous in Engineering

okay, for reasons unknown to you guys, i need you all to name off a few deadly or poisonous snakes. i not talkin like little copperheads or rattlesnakes. i'm talkin big ones like adders or cobras. can you help me?

2007-01-19 12:46:27 · 9 answers · asked by Anonymous in Zoology

to extract one calorie of heat from a body at the temperature of 0 F,when the temperature of the enviroment is 100 F.

2007-01-19 12:42:44 · 1 answers · asked by joy 1 in Physics

2007-01-19 12:41:12 · 2 answers · asked by Haveitlookedat 5 in Medicine

2007-01-19 12:41:00 · 4 answers · asked by futurama4282 1 in Mathematics

2007-01-19 12:38:50 · 4 answers · asked by Haveitlookedat 5 in Medicine

Im in 10th grade and I need an easy but good science fair project and I can not think of what I can do. I didnt even pick the topic. My teacher did. Any ideas? Oh yeah, and are there any good websites where I can get information about it?

2007-01-19 12:38:08 · 8 answers · asked by Anonymous in Earth Sciences & Geology

2007-01-19 12:37:58 · 20 answers · asked by leslie_pisoo 1 in Physics

1) Find the graphs of the two lines 4x = 3y + 23 and 4y + 3x = -19
The answer is that they are supposed to be perpendicular lines, but when I work it out, the slopes aren't negative reciprocals, they're only reciprocals. What am I doing wrong?

2) Which of the following points are not solutions of 2y - 5x > 6?
(2.6, 5) is supposed to be one of the solutions, but when I work it out, it seems that it doesn't fit. I keep getting -3 > 6. What am I doing wrong?

3) Find f(-4) when f(x) = -x^2 - 2x.
We haven't learned how to do these and I can't find where in my book it says how to do it. Could you tell me how without telling me the answer?

2007-01-19 12:36:27 · 11 answers · asked by Anonymous in Mathematics

If the principal quantum number of a shell is equal to 2, what types of orbitals will be present? Is it s and p, or just s? Also, if the principal quantum number of the outermost electron of an atom in the ground state is n=3, what is the total number of occupied principal energy levels contained in the atom? Is it 1, 2, 3, or 4?

2007-01-19 12:35:47 · 1 answers · asked by Anonymous in Chemistry

2007-01-19 12:33:14 · 5 answers · asked by haileybaby331 1 in Mathematics

we are asked to find the equation given only its roots..

these are the roots:
x = 3, ( 1 + i), ( 1 – i)

I just can't solve becaise of its imaginary sign..
please help..
thanks!

2007-01-19 12:33:00 · 4 answers · asked by carol 1 in Mathematics

Where do they use pacific standard time?? If it is 2am pacific standard time what time is it central standard time??

2007-01-19 12:32:23 · 5 answers · asked by blazn05 1 in Geography

3/28 ? 4/19

is it equal = to
is it <
or is it >

so confused.........i multiplied like a million times!

thnx in advance

2007-01-19 12:32:18 · 10 answers · asked by anonymous 2 in Mathematics

working between an upper temperature at 400 C and a lower temperature at 18 C?

2007-01-19 12:28:55 · 2 answers · asked by zizi m 1 in Physics

But does a certain surface like asphalt or concrete affect the freezing point? Like, does a surface need to be 32 degrees in order to freeze water??? HELP!?

2007-01-19 12:28:39 · 15 answers · asked by princess_angelfire10 1 in Weather

http://icr.org/article/42/

2007-01-19 12:26:36 · 16 answers · asked by rapturefuture 7 in Astronomy & Space

2007-01-19 12:22:13 · 9 answers · asked by jimmy f 1 in Mathematics

I know there's some smoke while it's burning. but when you blow them out and the wick is still glowing a little, lots and lots of smoke comes out. why is this? what's the difference between flame and glowing? and why does the glowing make so much more smoke?

2007-01-19 12:20:33 · 3 answers · asked by JizZ E. Jizzy 2 in Chemistry

please dont give me a fake answer...i need a true answer..thanks

2007-01-19 12:18:56 · 12 answers · asked by ajhkgfhjdfgksj 5 in Biology

2007-01-19 12:17:03 · 14 answers · asked by Anonymous in Astronomy & Space

2007-01-19 12:15:46 · 20 answers · asked by goofygoober 2 in Biology

2007-01-19 12:15:37 · 7 answers · asked by jimmy f 1 in Mathematics

The initial temperature is 18 C.Find the final temperature.

2007-01-19 12:15:32 · 1 answers · asked by zizi m 1 in Chemistry