Science & Mathematics - 30 January 2007

2007-01-30 10:22:18 · 5 answers · asked by Keith H 1 in Astronomy & Space

This is for Technology homwework. I need to descriiiiibe.............thanks!!!!!

2007-01-30 10:20:55 · 7 answers · asked by BOOM !! 1 in Other - Alternative

2c-d= -2 and 4c+d=20

2007-01-30 10:20:52 · 1 answers · asked by pretty_girl_ke 1 in Mathematics

2007-01-30 10:20:32 · 6 answers · asked by Anonymous in Mathematics

An arithmetic progression has been started with the first three terms: a,b,c. The third term is four times as large as the first term. When the third term is replaced by its reciprocal, then these three terms form a geometric progression. Find the smallest possible value of the fourth term of the geometric progression,

Haha, I challenge you to try to solve this!

2007-01-30 10:18:53 · 2 answers · asked by dotadh 1 in Mathematics

Let G be a finite group and H a proper subgroup such that |G| doesn't divide |G/H|!. Prove that H contains a nontrivial normal subgroup of G.

2007-01-30 10:18:08 · 1 answers · asked by John P 1 in Mathematics

It controls 4 electric fans which depend on the number of people inside a room, very useful in a classroom. It also has a timer to set how many hours the room will be used.

2007-01-30 10:17:41 · 1 answers · asked by cj_102505 1 in Engineering

2007-01-30 10:17:35 · 3 answers · asked by chanel_addiction 1 in Biology

1)Assume a 9 kg bowling ball moving at 2 m/s bounces off a spring at the same speed that it had before bouncing..
a)What is its momentum of recoil?
b) What is its change in momentum?
c)f the interaction with the spring occurs in 0.5 s, calculate the average force the spring exerts on it.

2) A group of playful astronauts, each with a bag full of balls, form a circle as they free-fall in space. Describe what happens when they begin tossing balls simultaneously to one another.

2007-01-30 10:16:33 · 1 answers · asked by Jane A 3 in Physics

2007-01-30 10:16:28 · 9 answers · asked by arggg 2 in Chemistry

what about faries and mermaids, and bigfootts?

2007-01-30 10:16:20 · 9 answers · asked by David Tent (but with less poles) 3 in Astronomy & Space

2007-01-30 10:15:13 · 7 answers · asked by Anonymous in Astronomy & Space

2007-01-30 10:12:45 · 5 answers · asked by Ed D 1 in Mathematics

Well.........my tEaCH wants us to find out what the "magic word" of trigonometry is.........I don't know??? Does anyone have an idea?!

2007-01-30 10:09:11 · 4 answers · asked by 09'Ready 3 in Mathematics

I have a question about an inverting amplifier.

|||--R3---------|.\
. . . . . . . . . . . .|...\_____V(out)
V(in)--R1-----|.../. . . . | .
. . . . . . . .. |. . .|./. . . . . | .
.................|_ __R2__| .

R1 is at V(in) of the amp, R2 is connected to V(in) and V(out) and R3 is attached to the ground and the (+) input, just like a normal inverting amp.
ok this is suppose to be an inverting amplifier, with
R1 = R2 =10kOhms
What should R3 be and why? I figured out that it is suppose to be the sum of R1//R2 = 5kOhms but I'm not sure why.

Any help explaining the reasoning behind it.

2007-01-30 10:08:58 · 4 answers · asked by kevins963 2 in Engineering

I grind my coffee beans just before brewing, to a fine powder. I use the drip method, with hot water poured over the coffee in a filter in a cone. When I take the cone off the pot after brewing and set it aside, some of the cooling grounds reconstitute themselves into beans again, complete with ridge.

What kind of molecular magic is happening here?

(And no, no beans are left unground when I put them in the filter. And no, I am not delusional. This has happened many times.

2007-01-30 10:08:15 · 2 answers · asked by dude242 1 in Chemistry

An atom with 15 total electrons has the same valence as which of the following?
A)Carbon
B)Nitrogen
C)Oxygen
D)Hydrogen
Please explain how you get the answer I don't understand how to do this? Thanks!!

2007-01-30 10:08:02 · 2 answers · asked by Fries 4 in Biology

Does anyone know any archaeologists who would like to give a mathematician (PhD) a job?

2007-01-30 10:07:24 · 1 answers · asked by M 6 in Earth Sciences & Geology

consider the list of numers: n(squared) +n+17, where n first equals 1, then 2, 3, 4, 5, 6, ... What is the smallest value of n for which n(squared) +n +17 is not a prime number?

2007-01-30 10:06:46 · 3 answers · asked by platypus 2 in Mathematics

2007-01-30 10:06:01 · 17 answers · asked by lalen p 1 in Geography

I'm doing a science fair project on peoples behavior. I'm also trying to find out if hand gestures or gestures in general show people's personality. So, i wanna know wut u know about human behavior or gestures, or a web site that may help.

2007-01-30 10:06:00 · 1 answers · asked by Lil Beauty 1 in Biology

Explain the difference between each

2007-01-30 10:05:27 · 3 answers · asked by Anonymous in Botany

http://www.ruthtimme.com/Mexico/pages/page_110.html
http://www.ruthtimme.com/Mexico/pages/page_112.html
http://www.ruthtimme.com/Mexico/pages/page_109.html

Many Thanks!

2007-01-30 10:05:10 · 1 answers · asked by plantgirl 3 in Botany

Okay, some know me cause I asked about this before. My question is "Is my dog red-green color blind?" I changed it a little bit but here it is:
1) Take black and white photos of an blue, yellow, green, and red paper. Compare shades.
2) Wrap each paper around a bowl until you have four bowls in dif. colors.
3) Fill each bowl with an equal amount of dog food.
4) Let the dog in so he can choose which bowl to eat from.
5) After he chooses, immediately record which one. He would choose the bowl closest shaded to his usual dog food bowl. His normal bowl is white. He would choose the paper closer to that, and if he can see green and red, then he would not choose them. Instead he would choose yellow (being closer to white than the others).
Does this sound good? If not, where and what can I improve? Please also give me your ideas for this. And also, if you don't want to help with the actual procedure, you could come up with a catchy name to put on my science fair board. Thanks everyone!

2007-01-30 10:03:32 · 1 answers · asked by NONAME 2 in Zoology

im doing an earth science project on geology in northeastern pennsylvania (specifically venango county). i need to know about what sorts of rocks are in that area and how they were formed...i know that they are mainly sedimentary and some metamorphic..but i still need more information than that, if at all possible. also, i already tried ask and google..no luck..so please, if you can help, it would be great. thanks!

2007-01-30 10:03:26 · 2 answers · asked by The Joy Massacre 2 in Earth Sciences & Geology

Imagine that you are hovering next to the space shuttle in an Earth orbit. Your buddy of equal mass, who is moving at 8 km/h with respect to the shuttle, bumps into you. If he holds onto you, how fast do you both move with respect to the ship?

2007-01-30 10:02:38 · 5 answers · asked by Jane A 3 in Physics

2007-01-30 10:02:28 · 17 answers · asked by Anonymous in Mathematics

A archer puts a .3kg arrow into the bowstring. An average force of 201N sis exerted to draw the bowstring 1.3m.

a) if there is no friction, what velocity does the arrow have when it leaves the bow?

When i worked it out using two different ways, the answer is conpletely different. They are supposed to be the same.

here's the first way:
To find the energy store in the bowstring
W=Fx
W= (201N) (1.3m)
W= 261.3J

W=KE
W= 1/2mv^2
261.3J = 1/2 (.3kg)v^2
V= 41.73m/s
_________________________
here is another way that i used.
I find the spring constant first
F=kx
201N = k(1.3m)
k= 154.62 N/m

EPE = 1/2kx^2
EPE = 1/2(154.62N/m)(1.3m)^2
EPE = 130.65J

EPE=KE
EPE=1/2mv^2
130.65J = 1/2(.3kg)v^2
v= 29.5m/s

i don't know which way is correct, this really drives me crazy. If the first way is correct, then why not the second way? and if the second way is correct, then why not the first way?
can somebody please explain??? i really need help.

2007-01-30 10:02:09 · 2 answers · asked by Ha!! 2 in Physics

Does anyone know how to figure out, without using the calculator 2 5/16 - 1 3/4= Show me please. and reduce of 56/12

2007-01-30 10:00:59 · 6 answers · asked by Christal R S 1 in Mathematics

which of the following is one root of the equation 5x^2+8=4x?

5-6i/4
-2+6i/5
2+6i/5
1+3i/10
4-5i/0

2007-01-30 10:00:54 · 3 answers · asked by devincr 1 in Mathematics