Science & Mathematics - 17 December 2007

government, e.t., cover ups? inner earth, WTF , i want the truth

2007-12-17 09:50:10 · 9 answers · asked by Anonymous in Astronomy & Space

i hear many explanations, but my mind cannot seem to fathom, or grasp the concept. any help?

2007-12-17 09:49:13 · 2 answers · asked by Anonymous in Physics

can someone explain to me the bonding between a Cu+2 ion and 20 moles of H2O?

2007-12-17 09:47:48 · 1 answers · asked by Anonymous in Chemistry

point (x_0,y_0), suppose x_0 = 0....blah blah

What is "_" ?
I have no idea how to read. Is x_0 = x(0)?
Or something else?

Please explain in detail about "_" notation
Thanks

2007-12-17 09:46:51 · 5 answers · asked by Anonymous in Mathematics

2007-12-17 09:45:55 · 2 answers · asked by keke z 1 in Physics

I have made a roller coaster model for my school project and for the roller coaster I need do make a VERTICAL PRIFILE/Blue Print (as it says on the project information sheet). So my Q is :

HOW Do You Make A Vertical Profile(/Blueprint) For A ROLLER COASTER?

I know a bit about the fact that it should be curved and straight line at different points and the loops need to be unwidened and measured as if it was straight with ups and downs on them, but can you explain more and accurate?

Thank You.

2007-12-17 09:45:33 · 1 answers · asked by Toczic 1 in Physics

I'm basically frankensteining together 2 electronic devices. I have some very basic skills with electronics, and can solder well. However, the two devices use different power supplies. Device A runs at 9 volts and 2 Amps, and Device B runs at 12 volts and .6 Amps. A friend of mine knows that Device B can also run fine at 8 volts.

My biggest question is will the difference in current be catastrophic? If likely, would a circuit such as the right most one here ( http://home.cogeco.ca/~rpaisley4/xCurrentReg.html ) work to get a constant current?

Any help with any of these questions would be very helpful.

2007-12-17 09:45:19 · 5 answers · asked by Harry S 3 in Engineering

The bob of a pendulum has a mass of 2.0 kg. The bob is pulled sideways so that it is 0.25 m above the reference level.

What is the speed of the pendulum at the middle of the swing (resting position where there's only kinetic energy?)?

2007-12-17 09:44:22 · 2 answers · asked by Anonymous in Physics

2007-12-17 09:44:07 · 7 answers · asked by Anonymous in Geography

suppose that the cicle is roled to the right along the line until the letter t is again in an upright position write three distances it could hav roled and explain

2007-12-17 09:44:06 · 1 answers · asked by siya 1 in Physics

Seriously. Its remarkable. We started off with nothing more than stone and fire. And look at us now.

2007-12-17 09:43:03 · 12 answers · asked by Marcus L 1 in Astronomy & Space

Some of their questions are absolutely appalling and are an embarassing indictment of the US public school system. Who agrees?

2007-12-17 09:38:13 · 5 answers · asked by ? 6 in Geography

I can view the city of Los Angeles from my backyard, and I notice that the street lights and residential lights flicker from a distance.

2007-12-17 09:34:08 · 20 answers · asked by Anonymous in Geography

A pair of oppositely charged parallel plates are separated by a distance of 5 cm with a potential difference of 550V between the plates.A proton is released from rest at the positive plate at the same time that an electron is released from rest at the negative plate.Disregard any interaction between the proton and the electron.

a) how long does it take for paths of the proton and electron to cross?

b) how fast will each particle be going when their paths cross?

c) How much time will elapse before the proton reaches the positive plate?
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I DONT GET WHATS MEANT BY THE FIRST 2 QUESTIONS, CAN YOU PLEASE EXPLAIN THE QUESTION AND THEN EXPLAIN ALL YOUR ANSWERS?

I PROMISE ILL GIVE A BEST ANSWER FOR THOSE WHO KNOW AND EXPLAIN!!
THANKS VERY MUCH FOR UR TIME

2007-12-17 09:32:56 · 2 answers · asked by G3P 3 in Physics

Please help me find the values of x and y.

(3x-11y)=47
(x+y+7)= 54

2007-12-17 09:30:36 · 6 answers · asked by Meghan M 1 in Mathematics

My chemistry teacher had to leave for a few weeks while her husband is having back surgery. She left my class notes and an assignment. She gave 10 people in my class a section of the current chapter to present/teach to the class. My section deals with Hess's law and enthalpy. I read the chapter, the notes, and the definitions, so I do not need those to be repeated. I need someone to please explain to me what enthalpy and Hess's law are, essentially. I kind of understand it, but not well enough to present. If someone could help I would be extremely greatful. Thanks!

2007-12-17 09:30:27 · 3 answers · asked by black_star_47001 3 in Chemistry

please help, I have been trying to figure this out for a very long time and some of the answers I have seen here seem to be interesting and convincing. Please help! :D

2007-12-17 09:29:37 · 3 answers · asked by showxmexwatchaxgot 1 in Other - Science

1, Which distance is greater: Chicago to New Orleans or chicago to Augusta, maine

is it Chicago to Augustam maine

2. A pipeline carries oil from Prudhoe Bay to the Port of Valdez in which state?
is it Alaska
I am not sure about the answers, pls help me out

2007-12-17 09:28:31 · 2 answers · asked by surmy 2 in Geography

2007-12-17 09:28:19 · 10 answers · asked by Kewlchikka 1 in Astronomy & Space

what are some of the uses for of copper.does it combine with other elements. what are they.

2007-12-17 09:28:18 · 4 answers · asked by jam4u06 2 in Chemistry

2007-12-17 09:27:39 · 2 answers · asked by Kampen 2 in Zoology

does anyone know what are some common elements found at home? thx

2007-12-17 09:25:16 · 1 answers · asked by Taylor 1 in Chemistry

Could you please include your steps so I can learn how to do the problem.
Thanx

2007-12-17 09:24:04 · 6 answers · asked by Fung 1 in Mathematics

Help!

2007-12-17 09:21:28 · 5 answers · asked by Anonymous in Mathematics

1.Suppose 200 J of work is used to compress a gas. If 125 J of heat escape in the process what is the change in internal energy of the gas?

I know it has to do with the change in internal gas equals work plus heat but I'm not too sure how to set it up.

what is the beat frequency when a 330 Hz sound and 332 Hz sound occur simultaneously?

What is the ideal efficiency of an automobile engine where fuel is heated to 700 K and outdoor air is 280 K?

A weight suspended from a spring is seen to bob up and down over a distance of 30 centimeters twice every three seconds. What is the period of oscillation? frequency? amplitude of oscillation?

Again, thanks to everyone who can help

2007-12-17 09:19:31 · 1 answers · asked by wienrshnitzel 1 in Physics

2007-12-17 09:18:49 · 2 answers · asked by oscarD 3 in Mathematics

give examples of species that illustrate and support your conclusion

2007-12-17 09:18:32 · 2 answers · asked by Mauricio G 1 in Biology

2007-12-17 09:18:16 · 14 answers · asked by Bakhtiar H 1 in Mathematics

x + 2 over 6 = x - 1 over 12

How the heck do you do this?

2007-12-17 09:18:09 · 6 answers · asked by Anonymous in Mathematics

A. zinc oxide
B. sulfur oxide
C. stannous flouride
D. hydrogen peroxide
E. carbon tetrachloride

2007-12-17 09:16:29 · 2 answers · asked by Danielle Boffice(: 1 in Earth Sciences & Geology