Science & Mathematics - 27 September 2007

Carl Sagan once said that it was hubris for us to believe the Earth was the only planet in the universe that was inhabited. He also put forth a mathematical formula regarding the probability of other inhabitable planets in the universe. Does anyone know his exact statement and the mathematical formula?

2007-09-27 09:42:49 · 4 answers · asked by CarolSandyToes1 6 in Astronomy & Space

When comparing the flow of lymph in the lymphatic system with the flow of blood in the circulatory system, it can be said that the lymphatic system also ...

A. uses a pump
B. contains fluid that travels in only one direction
C. uses valves to prevent backward flow
D. contains fluid that travels in a closed circuit

2007-09-27 09:41:12 · 1 answers · asked by crismarie 4 in Medicine

A capacitor has a capacitance of 3.1 x 10^-5 F. In the charging process, electrons are removed from one plate and placed on the other plate. When the potential difference between the plates is 580 V, how many electrons have been transferred?

2007-09-27 09:39:25 · 1 answers · asked by Anonymous in Physics

An empty parallel plate capacitor is connected between the terminals of a 15.7-V battery and charges up. The capacitor is then disconnected from the battery, and the spacing between the capacitor plates is doubled. As a result of this change, what is the new voltage between the plates of the capacitor?

2007-09-27 09:36:43 · 1 answers · asked by hemang p 1 in Physics

jarvis spent $1.04 on candy mints. Each mint cost less than $0.06. how many mints did he get? estimate: A 5 B 10 C 15 D 20

2007-09-27 09:35:18 · 18 answers · asked by bodigger 1 in Mathematics

And if it is a form of perpetual motion, would a device exhibit perpetual motion if it were in space rather than on Earth which has more gravity and air friction?

2007-09-27 09:34:14 · 4 answers · asked by eoc1000 2 in Physics

like i was reading that theyre like chopping off plants because
they're not from that state and stuff. but why is that so bad?

2007-09-27 09:34:00 · 3 answers · asked by beeeep. 1 in Botany

How much wood would a woodchuck chuck if a woodchuck could chuck wood?

2007-09-27 09:32:09 · 2 answers · asked by Anonymous in Zoology

Need Help I Chem

2007-09-27 09:30:52 · 6 answers · asked by web F 1 in Chemistry

a hamburger stand sold 25 more cheeseburgers than regular hamburgers. If it sold 100 cheeseburgers, how many regular hamburgers did it sell? solve show work

2007-09-27 09:30:27 · 2 answers · asked by bodigger 1 in Mathematics

starts with an R ends in E

2007-09-27 09:29:31 · 1 answers · asked by ash 2 in Engineering

Help, I just can't do it! I got a ridiculous answer like -8 +/- root 27.5

which is obviously not right!

2007-09-27 09:29:31 · 2 answers · asked by Anonymous in Mathematics

ok, so im sort of stuck on the last question. please help!!!

the carbon-14 isotope is radioactive and undergoes beta decay. the half life of the carbon-14 isotope is about 5700 years.

a) give the atomic number and the mass number of the species formed when carbon-14 undergoes beta decay.

b) how much of a 20g sample of carbon-14 would remain after 17190 years? please show how you get your answer.

c) the presence of the carbon-14 isotope is used to date old materials such as wooden boats and fabrics such as the "turin shroud" explain why the carbon-14 isotope is very suitable choice for dating such materials.

thanks :)

2007-09-27 09:28:38 · 4 answers · asked by Anonymous in Chemistry

what is the point of learning differential equations? I mean all my professor does is he writes the same types of problems and does the same thing over and over and I don't understand what the purpose is. I mean i know how to do these problems but what are they for. ie: first order diff., second order diff...etc...

2007-09-27 09:25:32 · 6 answers · asked by shadoyaj 4 in Mathematics

Just as a balloon expands and contracts because of the air pressure difference in and outside of it, could the (area, dimension, space) that the universe is expanding in to have a negative or positive (pressure) that controls the universe's expansion instead of gravity????

2007-09-27 09:23:27 · 3 answers · asked by bagua1 5 in Physics

\/\|/\o/\


line diagram....

2007-09-27 09:20:59 · 3 answers · asked by C'est Comme Un Rêve 3 in Chemistry

2007-09-27 09:20:28 · 8 answers · asked by KeepingTheFaith♥ 4 in Astronomy & Space

Ok, i need a little help with this. It's involving electricity, obvioiusly. So, an object has a resistance of 15 ohms, a voltage of 45 volts, an electric current of 3, the power of it is 135. After giving you these facts, I'd appreciate it if you could answer the question. The question is

What is the cost of operating this object for 10 hours at a rate of $0.08 per kWh?

I didn't understand the question, so maybe someone that understands electricity better than me can help solve this question. If you have taken the time to even read my question, thank you. Any help is highly appreciated.

2007-09-27 09:19:43 · 3 answers · asked by ? 4 in Engineering

2007-09-27 09:18:20 · 3 answers · asked by s.weiss 1 in Chemistry

i dont know if it something the teacher made up or if its some rare algebra term but it was a question asked today and no one could figure it out.
Here is a prolem:

Zingers: 9, 41, 57, 73, 17, 89, 33

Not zingers: 7, 22, 45, 8, 59, 36, 68, 13

Which of the following are zingers: 4, 55, 63, 25, 49, 24, 77, 92, 38, 42, 20, 65

What is a zinger? Explain.

You dont have to explain or watever and answer like which ones are zingers, but i just need to know wat the hell a zinger is and wat the patten or watever is. I really dont know anything about this so i pretty confused.

2007-09-27 09:15:03 · 5 answers · asked by Anonymous in Mathematics

2007-09-27 09:11:35 · 5 answers · asked by Anonymous in Engineering

Can anyone tell me some elements found on the periodic table that are found in living things besides oxygen???

2007-09-27 09:10:35 · 4 answers · asked by Kev 2 in Chemistry

As a rocket is fired from a launching pad, its speed and acceleration increase with time as its engines continue to operate. Explain why this occurs even though the thrust of the engines remains constant.

2007-09-27 09:06:40 · 3 answers · asked by back2back 2 in Physics

if i got it wrong, plz correct me and show me the correct way to do it.
Since the problem has a pic in it, i uploaded it on photobucket.
i think the answer is
AE+EC=4268.64

the link is: http://img.photobucket.com/albums/v601/silentfiend/t.jpg

thx!

2007-09-27 09:02:45 · 3 answers · asked by NT 2 in Mathematics

I'd appreciate it if someone could answer these 2 quesions. Thanks..

1.Which of the following is one possible form of pentane?

A) CH3CH2CH2CH2CH3
B) CH3CH=CHCH2CH3
C) CH3CH2-O-CH2CH2CH3
D) CH3CH2CH2CH2CH2CH3
E) CH3CH2CH2CH2CH2NH2

2. Calculate the molar mass for Mg(ClO4)2.

2007-09-27 09:02:28 · 4 answers · asked by Giulio M 5 in Chemistry

9875670 - 9875004 =

the answer is a good luck number, hahahahah!

2007-09-27 08:58:48 · 5 answers · asked by Enrique 3 in Mathematics

2007-09-27 08:56:51 · 9 answers · asked by Erin 2 in Mathematics

did life, that requires oxygen, start. ie: All living things need oxygen, including plant life, and plants make oxygen during daylight hours, Yes ?, but what gave plant forms, the oxygen that they required before they could even exist. Hey! come on you clever little so & so's.

2007-09-27 08:54:16 · 21 answers · asked by jerbal 1 in Astronomy & Space

Epsom salts, a strong laxative used in veterinary medicine, is a hydrate, which means that a certain number of water molecules are included in the solid structure. The formula for Epsom salts can be written as MgSO4•xH2O, where x indicates the number of moles of water per mole of magnesium sulfate. When 5.061 g of this hydrate is heated to 250*C, all the water of hydration is lost, leaving 2.472 g of MgSO4. What is the value of x? [Hint: Find the moles of water lost & moles of compound MgSO4 remaining. The ratio of water to compound = coefficient x]

2007-09-27 08:53:27 · 4 answers · asked by helpme77 1 in Chemistry

what is -2/3 divided by 12?????????? plz n thnks also -3/4 divided by 12

2007-09-27 08:53:13 · 7 answers · asked by nala 4 in Mathematics