Science & Mathematics - 21 September 2007

If I am not mistaken, one year is one full orbit by the earth around the sun. One year is also when the earth has gone through a full cycle of the seasons (summer winter spring etc) depending on your location on the Earth.

Is it just by coincidence that these two factors have the same time period? I mean, by the time the Earth has orbited the sun and come back to where it started, the seasons or tilting of the earth have finished their cycle at exactly that point. Is this just a coincidence or are these two factors somehow linked to each other in some way?

The middle of say, summer in a particular place is not exactly new years day, but the fact that the actual cycle lasts 365 and whatever days is my point. The season of summer starts a roughly the same time every year.

When was one year in our calender worked out and by who? Did they base it on the tilting of the Earth or the orbit? Also, given this information, what is today's definition of one year based on?

2007-09-21 23:59:55 · 10 answers · asked by Anonymous in Astronomy & Space

I have an engine make of cast aluminum and a steel bolt stuck in it. I drilled the bolt out but i cannot remove the shell with the threads. Is there something i can use to cause the steel bolt to rust/dissolve but not attack the aluminum block?

2007-09-21 23:54:41 · 1 answers · asked by Yuval L 1 in Chemistry

express each of the following as (x+a)² + c²

questions one;
x²+2x+3,
this is what i got
(x+1)² + 2

now what i'm confused about is should it be 2 or 2²


(note 2^2 = 2², short cut for squared is alt+253 (you type the numbers on the num pad - please pass this on)

2007-09-21 23:54:32 · 2 answers · asked by wonderboy 2 in Mathematics

say a cook with hiv cuts his finger with a knife and drops a single drop of blood into wet foods and a lukewarm soups, the soups areat very neutral temperatures. then the wet foods (non dry foods) and the lukewarm soups with fresh blood from the cook with hiv is served right away to customers. will the customers get hiv? they say that hiv in a single drop of blood outside the body will become impotent or will die if the hiv infected blood is outside the human body. they say that when blood dries up or when it clots as it is exposed to the outside environment, hiv will die. how will blood clotting or drying destroy or kill hiv? what if the hiv infected blood is dropped in soups or any other wet foods? how will the blood clot or how will that drop of blood dry up if it is dropped in wet foods and soups at very neutral temperatures? i have read from wikipedia that a single human cell is about 60 times bigger than a single hiv. come to think of it, imagine just 100 hiv within or among other 10 000 to 100 000 cells like rbc and wbc in a single drop of blood. how can external environmental factors penetrate into those 100 hiv among thousands of other cells? wont those other thousands of blood cells act as a barrier for external environmental agents to penetrate and destroy hiv? imagine food with a very fresh drop of blood infected with hiv be taken or eaten by restaurant or fast food customers.

2007-09-21 23:54:10 · 6 answers · asked by Anonymous in Medicine

NEED HELP......URGENTLY! xx

2007-09-21 23:53:44 · 6 answers · asked by Anonymous in Physics

Were ancient world ruling casta with same frenology?

2007-09-21 23:37:33 · 3 answers · asked by Sari 1 in Parapsychology

a) a type of weak bond involving the sharing of an electron with a hydrogen atom

If you could..kindly answer this link also. God bless!


http://answers.yahoo.com/question/index;_ylt=AsmCrsYCJjnl2UsBfzlIS2fsy6IX;_ylv=3?qid=20070920175026AAbGLYe

2007-09-21 23:30:20 · 5 answers · asked by Anonymous in Chemistry

2007-09-21 23:19:58 · 13 answers · asked by Faye 1 in Astronomy & Space

2007-09-21 23:18:38 · 11 answers · asked by Faye 1 in Astronomy & Space

We know that space is getting bigger for enormous sizes every day,but I wonder on behalf of what is it getting bigger?I mean,what is getting smaller if the space is getting bigger?

2007-09-21 23:17:07 · 6 answers · asked by Opera Phantom 5 in Astronomy & Space

What is the ph of 0.1 M HCN?

2007-09-21 23:13:18 · 2 answers · asked by Anonymous in Chemistry

where, and why are they haunted or known for being haunted?
Who haunts these places and why?

(I have read about some in various books...it was interesting!!)

thanks!

2007-09-21 23:01:09 · 7 answers · asked by ladyk 2 in Paranormal Phenomena

please can you help me as it is for my daughters homework which is needs handing in on monday!!!!!!!

2007-09-21 22:58:13 · 9 answers · asked by Beth 1 in Mathematics

in NaHCO3 combined with H2SO4

2007-09-21 22:52:36 · 1 answers · asked by Anonymous in Chemistry

I fancy dabbling in astronomy and so would like a telescope, im only a student so dont have much money but dont want to buy a rubbish one either, any suggestions?

2007-09-21 22:48:33 · 12 answers · asked by SweetLikeHoney 1 in Astronomy & Space

do you know if gambia is effected by these floods

2007-09-21 22:37:58 · 6 answers · asked by Anonymous in Geography

I just finished a 7 day course of Prednisone 40my/day for back inflamation. I already have the fluid retention, weight gain, and full face from this short dose. Is this normal and will I return to normal soon. Also the doctor didn't wean me off this dosage, which I don't know is rare for short term use. My glands are swollen, and I can't sleep. Do I risk infection and will my body return to normal soon after discontinuation of this medication. Also will the pain reemerge again due to the short term use and not weaning off the medication?

2007-09-21 22:19:51 · 5 answers · asked by sandpipers_r_free 2 in Medicine

2y-3(5y-8)=2(5+y)-10
2y-15y+24=10+2y-10
-13y+24=2y

im stuck after this, can someone help me out

in seems that i got this but im not sure if this right
24=15y

2007-09-21 22:17:49 · 12 answers · asked by cjay_cjay 2 in Mathematics

Chemistry Questions: seperation of a mixture by paper chromatography
After you have done the things down below
To assemble and operate a paper chromatography apparatus.
To study the meaning and significance of Rf values.
To test various food colorings and to calculate their Rf values.
To comparer measured Rf values with standard Rf values.
To separate mixtures of food colorings into their components.



***what can be identified the components of mixture s by means of their Rf values? Rf= d1/d2?

I am stuck on the last qustion please help me with three to four sentences please this is urgent thank you for your cooperation

2007-09-21 22:09:51 · 1 answers · asked by Anonymous in Chemistry

Hello, I've been taking algebra1 and its sorta hard since im not a math person. Can you help me by answering these equations and please show your work!

x+(x+1)+(x+2)=9

(y-2)+(y-1)+y= -3

19n-11-12n-5=5

7h-17-6+4h=17

-2t+3(2+t) = -10

2(x+3)-6x-4 = 8

4z+2(z+7)= -14

-5(1+w)+4w= 8

-3(2-y)+2y= 7

5a-(1-a)+4 = 9

-7 - (-3 - 2g) - 10 =0

1.5k - (k +2.4) = 17.4

3s - (0.5s+7.2) = 32.8

*Remember: Show your work!

2007-09-21 22:06:11 · 8 answers · asked by infamous_l00z3r 2 in Mathematics

Does it split the double helix or attach the free floating nucleotides to make the single strand?

or does it do something else?

2007-09-21 22:04:36 · 3 answers · asked by Hemanshi B 2 in Biology

nuclei is in the center and the electrons revolving around the nuclei

2007-09-21 22:03:45 · 3 answers · asked by Anonymous in Physics

2007-09-21 21:58:42 · 18 answers · asked by Anonymous in Zoology

How do you solve the equation: x+(x+1)+(x+2)=9
Please show your work.
all the people I've asked to solve this equation, they were either too dumb or too busy to answer. How lame are they?

2007-09-21 21:55:48 · 14 answers · asked by infamous_l00z3r 2 in Mathematics

2007-09-21 21:49:46 · 7 answers · asked by Petarded 1 in Astronomy & Space

When siva bought a fish from a shop, he placed the plastic bag containing the fish in the tank for 15mins before he released the fish into the tank

a. Why did he do this?
B. What are two sources for the fish in the thank

PS: Thanks again guys for helping! THIS IS AN IMPORTANT QUESTION!! CAN SOMEONE PLS TELL ME WHETHER REAL LIFE MONEY IS NEEDED FOR ASKING QUESTION/ANSWERING QUESTION AT THIS WEB AND WHETHER EXPANDING THE DAYS WILL COST REALIFE MONEY

2007-09-21 21:40:53 · 3 answers · asked by Anonymous in Other - Science

a space station, it is like a mini-earth inside it, have animals, plants,etc.

First want to thank everyone who helped me so far.. I will be posting more questions later after i finish the project next week (i will e-mail the ppl that gave me good answers but the ones I couldnt choose as best answer)

There are still things left...... that I need help on

For my spacestation... Can it be just like a dome?? An enclosed dome.. What r the benefits of an enclosed dome.. I know that it can control sunlight/keep oxygen

Also I need to have rooms for things... like what kind of rooms are going to be there in my space station?

also I have to find 6 jobs.. have doctor/scientist/engineer/botanist.. need 2 more
I also need to have trophic levels and biomass for the organisms............

So what organisms should I bring??? can u like list them?

2007-09-21 21:39:56 · 2 answers · asked by Joe H 1 in Earth Sciences & Geology

4x+5(3+2x)=3
4x-15-10x=3
-6x -15 =3
-6x = 18
x = 3

Did I do this correctly, if i didnt tell me where I made my mistake?

2007-09-21 21:37:31 · 19 answers · asked by cjay_cjay 2 in Mathematics

John says," Wind energy actually comes from the Sun"
Which of the following is true of John's statement
1. False: Wind energy and solar energy are different sources of enery.
2. False: Wind energy is kinetic energy of air
3.True : Wind is caused by some parts of the atmosphere having higher temperature than other parts.
4.True: solar energy can be converted into kinetice energy

Study the Venn diagram show below
Pong Pong and dumbcane are grouped the same while pineapple is in another
A.How are the Pong Pong and Dumbcane are different from the pineapple?
B. put a dot in the Venn diagram and write "papaya"

The classficaction chart shows 2 groups of plants. They are classified according to their method of reproduction
Group A: mango and balsam
Group B: Mould and moss
Write a suitable heading for A and B
A-
B-
In which group would you place 'algae'?

Ps: please help again thanks lots part 3 last few questions

2007-09-21 21:34:32 · 3 answers · asked by Anonymous in Other - Science

9x(3-2x)=10(9x+4)

expand into two brackets and solve x, (both of them)

2007-09-21 21:32:39 · 5 answers · asked by wonderboy 2 in Mathematics