Science & Mathematics - 20 November 2007

2007-11-20 03:59:50 · 7 answers · asked by Ash 1 in Geography

http://www.wmf.org/resources/photogallery/images/spain_segovia_aqueduct.jpg

2007-11-20 03:58:41 · 3 answers · asked by Alexander 6 in Engineering

2007-11-20 03:58:14 · 6 answers · asked by foxboi75 1 in Mathematics

Also what's the difference between a pond and a lake

2007-11-20 03:56:07 · 9 answers · asked by Anonymous in Geography

Hi guys....i really require ur help. I wanted to make a ferrofluid. But i cud nt get any oleic acid. Can I use CITRIC acid instead of oleic.Also, i heard the ferrofluid will not be as strong as expected to get spikes. Is this true? Can u give me some tips. I have been using this tutorial for the preparation :

http://chemistry.about.com/od/demonstrationsexperiments/ss/liquidmagnet_2.htm

2007-11-20 03:55:43 · 2 answers · asked by Viveque 1 in Chemistry

Is it a stressful course to venture in?
Do u need to study all the time?
Is it worth it?
I love aircraft by the way........

2007-11-20 03:53:33 · 4 answers · asked by Anonymous in Engineering

A decomposition reaction separately occurred for 2 samples (a & b) which contained NaHCO3 (solid) (84 g/mol). Both samples weighed the same but one was pure and one was impure. The product of the decomposition of sample a weighed .25 g and the product of sample b weighed .29 g. Assuming all impurities evaporated during heating:

a. determine the grams of NaHCO3 originally in the pure sample

b determine the grams of impurity in the impure sample

c. determine the % of purity

2007-11-20 03:40:14 · 2 answers · asked by Hey D 1 in Chemistry

2007-11-20 03:39:37 · 10 answers · asked by Anonymous in Weather

I'm pretty familiar with chemistry and physics, however, why do we assume that all of the elements must be on earth ? Isn't it possible that there exist some elements at the end of the table we haven't discovered yet ?

2007-11-20 03:34:07 · 8 answers · asked by Razor 2 in Physics

At the age of eight, after correcting a school teacher's math blunder, the irritated teacher decided to humiliate Pascal and gave him this problem. "Take 1, add it to 2, then 3, then 4 on and on to 9,999." Mathematically it could be written: 1+2+3...+9999=?. Within seconds Pascal solved the problem in his head and spit out the answer, having had a brilliant insight. Can you do it in your head too? There's no way I can tell if you are cheating or not, but first right answer gets the prize!

2007-11-20 03:29:24 · 5 answers · asked by Anonymous in Mathematics

2007-11-20 03:27:44 · 4 answers · asked by landon s. 1 in Zoology

2007-11-20 03:20:33 · 6 answers · asked by Deel 1 in Astronomy & Space

If I were in a zero-gravity environment with a tennis ball.
The tennis ball would be attracted to my gravity, bringing it close to me?

2007-11-20 03:20:14 · 8 answers · asked by Jansen J 4 in Physics

What is rest mass Mo of the PAIR of photons?

2007-11-20 03:19:50 · 4 answers · asked by Alexander 6 in Physics

2007-11-20 03:13:24 · 4 answers · asked by Anonymous in Physics

When we are inside a room why is there the same air pressure as when we are outside. Surely the roof takes all the pressure from the gas etc above and therefore it is not on us.

2007-11-20 03:12:07 · 4 answers · asked by Anonymous in Physics

2007-11-20 03:11:17 · 8 answers · asked by Anonymous in Engineering

show wrk plz

2007-11-20 03:11:00 · 7 answers · asked by Anonymous in Mathematics

it is a secret sentence/readings to make someone stronger. for info, the readings or spell (whatsoever) is read by using arabic, jawa language or combined.
know what, i saw a 13yrs boy use a spell on his schoolmates. the spell make someone like him(become friendly). one day i witness he have a fight with someone, then he cut his eyebrow and read something and blow the eyebrow (he is about 10m from the other boy), then the angry boy become very nice and friendly.
he also have very weird attitude- he always pratice his martial art(silat) every night alone at the back of hostel.
=,= he also use his spell on a girl and the girl love him very well even do he is not that handsome .geez

2007-11-20 03:09:06 · 8 answers · asked by ZyamsouI 3 in Paranormal Phenomena

please show ur work :)

2007-11-20 03:09:00 · 32 answers · asked by Anonymous in Mathematics

A cat chases a mouse across a 1.0 m high table. The mouse steps out of the way, and the cat slides off the table and strikes the floor 2.2 m from the edge of the table. When the cat slid off of the table, what was its speed?

2007-11-20 03:08:50 · 3 answers · asked by x x italian baby x x 1 in Physics

Consider 5 points, A, B, C, D, and E such that ABCD is a parallelogram and BCED is a cyclic quadrilateral. Let l be a line passing through A. Suppose that l intersects the interior of the segment DC at F and intersects line BC at G. Suppose also that EF = EG = EC. Prove that l is the bisector of angle DAB.

2007-11-20 03:08:39 · 1 answers · asked by Isaac Proff 1 in Mathematics

A person doing a chin-up weighs 710 N, disregarding the weight of the arms. During the first 27.0 cm of the lift, each arm exerts an upward force of 365 N on the torso. If the upward movement starts from rest, what is the person's speed at this point?

2007-11-20 03:05:23 · 1 answers · asked by andyjumpman23 3 in Physics

2007-11-20 03:02:03 · 1 answers · asked by lijo 1 in Chemistry

I have to write a chemical equation for a reaction in which HCLO3 is a Bronsed-Lowery acid in water and a chemical equation for a reaction in which CLO3- is a Bronsted-Lowery base in water. Can someone help please.

2007-11-20 02:59:18 · 1 answers · asked by Anonymous in Chemistry

Determine how many grams of Na2CO3 (solid) (106 g/ mol) and CO2 (gas) (44g/mol) are produced from the decomposition of 1.67 grams of NaHCO3 (solid) (84 g/ mol).


thanks in advance!!!

2007-11-20 02:55:41 · 2 answers · asked by Hey D 1 in Chemistry

what is limit as n--> infinity of n[(n+1)^0.5 - (n^0.5)] ^2

2007-11-20 02:54:26 · 4 answers · asked by dposters 1 in Mathematics

The active element of a certain laser is an ordinary glass rod 25 cm long and 1.0 cm in diameter. If the temperature of the rod increases by 73°C.
(a) Find its increase in length.

(b) Find its increase in diameter.

(c) Find its increase in volume.

2007-11-20 02:53:05 · 1 answers · asked by ricahrd l 1 in Physics

A helium-filled balloon at atmospheric pressure is tied to a 2.7 m long, 0.100 kg string. The balloon is spherical with a radius of 0.40 m. When released, it lifts a length (h) of the string and then remains in equilibrium as in Figure P9.78. Determine the value of h. When deflated, the balloon has a mass of 0.25 kg. (Hint: Only that part of the string above the floor contributes to the load being held up by the balloon.)

2007-11-20 02:50:56 · 3 answers · asked by ricahrd l 1 in Physics

Hi.

I'm solving equations where I'm asked to first of all clear out any fractions or decimals, I already know how to clear out fractions, you just multiply by by the Least Common. Denominator. But how can I clear out decimals.
let's say

05x+0.3y+0.7z=10
0.2x+0.4y+0.5z= 10

in this example or in any example how can you clear out decimals?
thank you.

2007-11-20 02:50:25 · 4 answers · asked by Anonymous in Mathematics