Science & Mathematics - 8 September 2007

2007-09-08 04:49:38 · 3 answers · asked by Anonymous in Biology

I never learned how to do a problem like this:

12x^2 + 57xy - 21y^2

2007-09-08 04:48:58 · 7 answers · asked by Anonymous in Mathematics

2007-09-08 04:47:21 · 3 answers · asked by Anonymous in Biology

2007-09-08 04:46:22 · 8 answers · asked by imogen w 2 in Physics

Nitrogen gas (N2) can be prepared by passing gaseous ammonia (NH3) over solid copper (ll) oxide (CuO) at high temperatures. The other products of the reaction are solid copper (Cu) and water vapor (H2O)
a. If 18.1 g of NH3 is reacted with 90.4 g of CuO, which is the limiting reactant?
b. How many grams of N2 will be formed?
plz help me !!!!!

2007-09-08 04:44:25 · 2 answers · asked by shima 1 in Chemistry

-2(x-4)=3(5-x)


was x=7 the answer i was supposed to get?

2007-09-08 04:44:16 · 6 answers · asked by Victoria 1 in Mathematics

2007-09-08 04:44:12 · 11 answers · asked by Holy..Rock 2 in Mathematics

I have to make a diachtomous key and i have to tell the insects apart. Can someone please help?

2007-09-08 04:43:54 · 4 answers · asked by the i code 3 in Biology

Find each of the following squares (7p+6q)^2

2007-09-08 04:41:17 · 4 answers · asked by Anonymous in Mathematics

Aluminum reacts with oxygen to produce aluminum oxide. If you want to produce 5.00 moles of aluminum oxide, how many moles of aluminum and how many moles of oxygen will be required?

2007-09-08 04:37:52 · 2 answers · asked by Jack L 1 in Chemistry

I am working on a project using two motors taken from two hand held hair dryers, currently I am using 6 volts DC to power the motors for my project but I need more power(more than 50 volts DC) without the weight of adding extra batteries is there a way to increase the voltage without adding more batteries or plugging my project into the wall? and will increasing the voltage increase the motors rpms?

2007-09-08 04:34:49 · 4 answers · asked by FSU53 1 in Other - Science

I was playing football at an outdoor futsal court just now during the night and the sky suddenly flashed dark red, which slowly dimmed down to normal sky, which lasted for about 10 seconds. What could it be? I was thinking of fireworks the moment I see it but realised that it's impossible when it stretched out covering most parts of the sky. Any expert views or similar experience?

2007-09-08 04:34:19 · 9 answers · asked by LeBear 2 in Astronomy & Space

Can anyone tell me a mole equation for solids ??????

2007-09-08 04:29:20 · 6 answers · asked by Anonymous in Chemistry

Which one is worse?

I think heat is worse.. I can't stand it. I've been through 100 degree temperatures and its HELL.
I've also been through -10F temps and believe it or not, I found it enjoyable..

2007-09-08 04:27:51 · 9 answers · asked by Anonymous in Weather

Okay, so we have to use this picture, and put a number from 1-10 in each circle so that all the numbers in the rows of four add up, and all the numbers and the all the numbers in the rows of three add up. Each number can only be used once.
The threes and fours do not have to be equal to each other.
http://i69.photobucket.com/albums/i73/PirateyGoodness/hdhf.jpg

Sorry the pictures so sloppy, I just made it in paint.

2007-09-08 04:25:10 · 2 answers · asked by Rob 3 in Mathematics

In exercise 77 and 78 write an equation whose graph has the indicated property.
77. The graph has intercepts at x = -2, x =4, and x = 6
This is the answer for number 77:
y = (x + 2)(x - 4)(x - 6)
I don't understand why though. Why does the signs change from negative 2 and positive 4 to negative four?
I need help solving the one listed below also please

78. The graph has intercepts at x = -5/2, x = 2, x = 3/2

2007-09-08 04:24:41 · 1 answers · asked by Venia c 1 in Mathematics

{0,1,2,3,4} is the replacement set for n. Find the value of n if:
a. 2 x 4 = n (mod 5)
b 4 + 3 = n (mod 5)
c. 1 - 3 = n (mod 5)

I would appreciate a good explanation more so than just the answer. Thanks.

2007-09-08 04:23:26 · 3 answers · asked by Tanya T 1 in Mathematics

Multiply (x/3+3/4)(3x/4 - 3/5)?

2007-09-08 04:21:56 · 4 answers · asked by Anonymous in Mathematics

2007-09-08 04:18:01 · 1 answers · asked by Anonymous in Biology

when using a calculator what do you have to becareful of

2007-09-08 04:17:31 · 8 answers · asked by Anonymous in Mathematics

2007-09-08 04:13:59 · 7 answers · asked by Meeka 2 in Zoology

I need a strong plastic, available in sheets, that is not transparent, (polycarbonate is only available tinted/clear).

2007-09-08 04:08:34 · 1 answers · asked by basilb101 3 in Engineering

2007-09-08 04:05:24 · 2 answers · asked by Anonymous in Physics

All living organisms on Earth contain carbon. If Carbon-12 amu mass = 12, makes up 98.89%, and Carbon-13, amu mass = 13, makes up the other 1.11%, what is the average atomic mass of carbon?

I'm a little confused how to go about this question. What does the information show me and how do I use it to get the answer.

2007-09-08 03:58:44 · 2 answers · asked by Average Joes 4 in Chemistry

A 1.25-kg object is moving in the x direction at 17.4 m/s. Just 3.41 s later, it is moving at 26.8 m/s at 34° to the x axis. What are the magnitude and direction of the force applied during this time?

2007-09-08 03:54:21 · 3 answers · asked by Anonymous in Physics

2007-09-08 03:52:18 · 12 answers · asked by Anonymous in Mathematics

Why isn't NASA located in Miami? That's where the space shuttle launches. Houston just has cowboys and horses and stuff.

2007-09-08 03:46:48 · 6 answers · asked by Anonymous in Astronomy & Space

why people worries about shortage of water in 50 years to come while the whole world is sorounded by ocen ,which people say it never dry, is it not possible to treat oceon water so as it can be usefully domestically

2007-09-08 03:45:31 · 6 answers · asked by Rajabu H 1 in Earth Sciences & Geology

South America: venezula,columbia, equador,peru,boliva,paraguay,chile,Uruguay,Argentina.


Central America: Mexico,Cuba,Guatemala,hondoras,panama,costa rica,el
Salvador, Dominican republic,puerto rico, Nicaragua.


Europe: Spain


Africa Ecutorial Guinea

2007-09-08 03:42:05 · 4 answers · asked by Anonymous in Geography

2007-09-08 03:39:26 · 2 answers · asked by Anonymous in Earth Sciences & Geology