Science & Mathematics - 18 November 2007

Since we have a lot of tools to look into the galaxy have scientists ever came across stars wtih the exact chemical make up and age of our sun? Would these stars have formed in the same nebula that the sun was birthed in? And why did they drift away?

2007-11-18 14:09:34 · 6 answers · asked by Prince Auggie 2 in Astronomy & Space

i cant remember the name of it, if you put it on a cloth and put it to someone's mouth it knocks them unconscience

2007-11-18 14:08:21 · 1 answers · asked by brian c 1 in Chemistry

A rectangular movie theather is 120 feet long. The top and bottom of its screen are 45 feet and 20 feet from the floor. Find the position in the theater with the largest viewing angle.

Hint: You are asked to find the position x where the angle a-b is the largest. Instead of maximizing a-b, it is easier to maximize tan (a-b).
It is easier to maximize tan (a-b). The subtraction formula for tangent will be needed. This may be found by executing expand(tan(a-b));

CAN SOMEONE PLEASE HELP ME!!!!! HOW do i solve this using maple!?!?! i dont even know how to get started!!!

here's what the situation looks like :

http://i3.tinypic.com/86pwnpk.jpg

2007-11-18 14:07:59 · 2 answers · asked by soccerdude 1 in Mathematics

Should drug companies be allowed to advertise prescription drugs on television, radio, or magazines? Don't we have enough hypochondriacs in the world as it is?

2007-11-18 14:07:58 · 1 answers · asked by Anonymous in Medicine

(a) Calculate the mass of Li formed by electrolysis of molten LiCl by a current of 8.2 104 A flowing for a period of 14 hr. Assume the electrolytic cell is 70. percent efficient.

answer = 210000

(b) What is the energy requirement for this electrolysis per mole of Li formed if the applied emf is +8.4 V?
answer in kWh/mol

2007-11-18 14:04:02 · 1 answers · asked by softshimmer 2 in Chemistry

how do u use the center of gravity approach to Determine the optimal location (latitude and longitude) to minimize driving distance per week given constraints.

2007-11-18 14:03:44 · 1 answers · asked by Na la 3 in Physics

2007-11-18 14:03:39 · 6 answers · asked by kindakaotik 1 in Mathematics

For the problem, 6x + 6y - 12z = 36,
I must sketch the graph of each equation and find the equation of each trace.

I understand how to graph it, but what does it mean to the equation of the trace?

2007-11-18 14:01:00 · 1 answers · asked by anya 2 in Mathematics

2007-11-18 13:58:46 · 1 answers · asked by rachie11207 2 in Mathematics

2007-11-18 13:57:36 · 1 answers · asked by manis 1 in Engineering

I'm on 20 mg of prozac and I just took 25 mg of vistaril (just to test the affect, since I do have an exam tomorrow)
is this a safe combination?
...well it should be since the dr perscribed it.

2007-11-18 13:56:46 · 5 answers · asked by Anonymous in Medicine

(since the Earth is fatter at the equator than at the poles) Explain how the Mississippi can flow "uphill". I have no idea how to answer this problem, please help if you can! Thank you!

2007-11-18 13:56:25 · 3 answers · asked by Kiwikahuna 2 in Physics

And what does it do to you?

2007-11-18 13:47:25 · 14 answers · asked by xpartyinmypantsx 2 in Parapsychology

2007-11-18 13:46:40 · 3 answers · asked by Kk 2 in Mathematics

2007-11-18 13:46:07 · 2 answers · asked by Anonymous in Engineering

these last questions i couldnt find in my textbook... help please!!

27. Why can a p sublevel hold six electrons while the s sublevel can hold no more than two electrons?

28. What do electrons and light have in common?

29. Of a set of four quantum numbers, how many of these numbers can be shared by more than one electron of the same atom?

30. When does an electron in an atom have the lowest related?

31. How are the frequency and wavelength of light related?

32. Why does an electron occupy the 4s orbital before the 3d orbital?

33. The element sulfur has an electron configuration of 1s2 2s2 2p6 3s2 3p4

2007-11-18 13:39:05 · 2 answers · asked by rebeccapolsh333 2 in Chemistry

It's just taking a pic and then saving it as different forms, like PNG, JPEG, TIFF, etc. and then comparing like the file sizes, pic quality, etc.

I know it's a middle school project but I hate science and I just want something quick and easy, where I don't stutter over confusing terms and ideas.

Computer science is acceptable, yes?

2007-11-18 13:38:38 · 1 answers · asked by Me 7 in Other - Science

1)heating 100.0 grams of copper(ii) sulfate pentahydrate and obtaining 58.2 grams of anhydrous copper(ii) sulfate. What percent yield was obtained in this experiment? CuSO4 x 5H2o + heat --> CuSO4 + 5H2O
2)Find the percent composition by mass of phosphoric acid, H3PO4
3) Find the emperical formula for a compound that has the following percentage composition by mass: 10.04% carbon; .84% hydrogen; 89.12% chlorine.


Any help would be thankful. I just do not understand how to do these specific types of problems.

2007-11-18 13:38:28 · 1 answers · asked by chipmunkriot 2 in Chemistry

did he spend on the watches than on the clocks ?

2) David spent $210 in clothes & 30% of the remainder on food. Then he saved the rest of his money. If he had saved 49% of his original sum of money, how much did he have at the beginning ?

2007-11-18 13:37:45 · 5 answers · asked by Lim S 3 in Mathematics

Assume that each situation can be expressed as a linear cost function. Find the cost function for each case. Marginal cost $90.00 ; 150 items cost $16,000.00 to produce.

2007-11-18 13:34:55 · 1 answers · asked by Anonymous in Mathematics

Solve the following counting problems. In each case show the reasoning that led you
to the answer.

(a) A palindrome is a word that reads the same forwards and backwards. How many
seven-letter palindromes can be made from the English alphabet?

(b) How many bit strings of length 10 begin with three 0s or end with two 1s?

(c) How many bit strings of length 10 contain either five consecutive 0s or five consecutive
1s?

(d) How many truth tables are there for propositions with n variables?

(e) Suppose you have n beads, each of a different color, that you need to string into a
necklace? How many distinct necklaces can you make? (A necklace flipped over
remains the same and does not count as a distinct necklace.)

2007-11-18 13:34:32 · 2 answers · asked by David 2 in Mathematics

2
8+5i

Where 'i' is an imaginary unit.

Write the quotient in the form of a+bi.

2007-11-18 13:33:28 · 3 answers · asked by Anonymous in Mathematics

The standard heat of formation of CaBr2 is -675 KJ/mol. The first ionization energy of Ca is 590KJ/Mol and its second ionization energy is 1145KJ/Mol. The heat of sublimation of Ca[Ca(s)---->Ca(g)] is 178 KJ/Mol. The bond energy of Br2(l) is 31 Kj/Mol, and the electron affinity of Br is -325 Kj/Mol.

Calculate the lattice energy of CaBr2??

E=? kj/mol

2007-11-18 13:31:02 · 2 answers · asked by FANTASY 2 in Physics

2007-11-18 13:30:35 · 2 answers · asked by hondarider400at 3 in Chemistry

2007-11-18 13:30:14 · 22 answers · asked by suzywong 4 in Weather

NaCl has a lattice energy of -787Kj/mole. consider a hypothetical salt XY. X^-3 has the same radius of NA^+ and Y^-3 has the same radius as Cl^-.

Estimate the lattice energy of XY?

E= ?KJ/Mol

2007-11-18 13:29:33 · 1 answers · asked by FANTASY 2 in Chemistry

2007-11-18 13:29:00 · 2 answers · asked by fgvtrghjbk 1 in Weather

A 7500kg truck traveling at 5 m/s east collides with a 1500kg car moving at 20 m/s direction south of west. After the collision, the two vehicles remain tangled together. A) With what speed and direction does the entangled wreckage move immediately after the collision? B) If the coefficient of friction between the sliding wreckage and the road is .85, how far will the wreckage go before it slides to a stop?

I got:
A) (7500kg)*(5m/s) + (1500kg)*(20m/s) = )7500kg+1500kg)V
V= 7.5 m/s
is that right?

2007-11-18 13:28:36 · 1 answers · asked by Anonymous in Physics

can someone explain to me what the higgs boson is? i read something about it being the reason particles have mass, would that be true?

2007-11-18 13:26:50 · 2 answers · asked by Anonymous in Physics

Part I)
How do you show that H is not normal in A_4?

Part II)
Referring to the Multiplication table for A_4 as a set of even permutations (http://www.math.niu.edu/~beachy/aaol/grouptables2.html)
how do you show that, althought, X_6H = X_7H and X_9H = X_11H, it is not true that X_6X_9H = X_7X_11H. Why does this prove that the left cosets of H do not form a group under coset multiplication??

(For easier typing, for this problem I am letting alpha = X and the even permutations in the chart are labeled as follows:
(1) = X_1
(12)(34)= X_2
(13)(24)= X_3
(14)(23)= X_4
(123)= X_5
(243)= X_6
(142)= X_7
(134)= X_8
(132)= X_9
(143)= X_10
(234)= X_11
(124)= X_12

2007-11-18 13:23:32 · 1 answers · asked by Anonymous in Mathematics