Science & Mathematics - 3 February 2007

It was 5 years ago in 2002 when i was in bed and i don't feel sleepy and decides to look outside of my window to the sky, there was alot of stars and i saw one that was flashing green and white and it was moving like circling and (note: i couldn't hear any airplane or helicopter sound that time) and flash green and white faster, then it disappear. I did not make this up, I just wrote what I saw that day.

I was amazed what i saw in the sky that day so I decided to studied and learned about the planets, our solar system, the galaxies, and the universe and one day prove that U.F.O realley does exist.

And finally how did life on Earth started? did others life somewhere in the Universe, millions of years ahead of us started the life on Earth which we live on today. Thousands, millions or billions years later they must have came back with U.F.O .

Its amazing that our world (Earth) is so small, and there are other planets out there in the universe which some contains life.

2007-02-03 19:05:18 · 12 answers · asked by Lee 2 in Astronomy & Space

A belt which is 15 feet long is tightely tied to a cylinder. The diameter of each circle (which is at the both ends of the cylinder) is 1 feet. What is the distance between the centers of 2 circles??? Can anyone help me out with this??

2007-02-03 19:03:21 · 6 answers · asked by rajagopal r 1 in Mathematics

construction engineering, or highway engineering, or forestry engineering

2007-02-03 19:02:18 · 1 answers · asked by djventura40 1 in Engineering

Need the answer ASAP please

2007-02-03 19:00:13 · 4 answers · asked by Anonymous in Chemistry

two hunters 100k apart walking towards each other at 5k/hr and 15k/hr speed respectively. one has a hunting dog running towards the other at 30k/hr speed. once the dog meets the other hunter it starts to run back. so on and so forth. the dog runs till the hunters meet. how long has the dog run?

2007-02-03 18:59:12 · 1 answers · asked by kgfzgao 1 in Other - Science

How many isomers of the alkene pentene C5H10 are there?


How many isomers of C4H10O are there? How are they classified?

2007-02-03 18:58:06 · 2 answers · asked by Nodoudt 2 in Chemistry

Is it a kind of frut, or a type of fish?

2007-02-03 18:57:33 · 3 answers · asked by chardonnayormerlot 2 in Other - Science

Pilots of fighter planes are subjected to large centripetal accelerations during high-speed turns. Because of these accelerations, the pilots are subjected to forces are greater than their body weight, leading to an accumulation of blood in the abdomen and legs. As a result, the brain is starved for blood, and the pilot can ("black out"). To appreciate the forces that a fighter pilot must endure, consider the magnitude of the normal force that the pilot's seat exerts on him at the bottom of a dive. The plane is traveling at 236 m/s on a vertical circle of radius 738 m. Determine the ratio of the normal force to the magnitude of the pilot's weight. For comparison, note that black-out can occur for ratios as small as 2 if the pilot is not wearing an anti-G suit.

My work:

Ratio = FN/W
FN=ma ---> m(v^2/r)
W=mg

so ((mv^2)/r)/(mg) the m's cancel so (236^2)/738/9.8= 7.7009

but that answer wasn't correct. I need help and any help would be appreciated. Thanks.

2007-02-03 18:55:41 · 4 answers · asked by ncg 2 in Physics

Will it one day be possible? Im no expert on science so dont be judgemental. ANyway I head that if you can get an object to go faster than the speed of light you could time travel. Perhaps?
Now what about that grandfather theory, if thats what its called.( I think the theory is something like this..) If you went back in time and you grandfather got killed or you killed him would you be alive??

If time travel was possible would it even be known to the public or would they keep it a secret? I think they should keep it a secret because if we could all do it then everyones past/present/future would be altered so we would all be essentially living in different dimensions. ?

2007-02-03 18:55:12 · 6 answers · asked by No need to be rude people, dam 1 in Physics

A satellite is in a circular orbit around an unknown planet. The satellite has a speed of 1.67 x 104 m/s, and the radius of the orbit is 4.39 x 106 m. A second satellite also has a circular orbit around this same planet. The orbit of this second satellite has a radius of 7.98 x 106 m. What is the orbital speed of the second satellite?

My work:
I had some crazy idea that proportions would work

V1/R1= V2/R2 which gave me 30356.7 which was incorrect

I really have no clue on how to approach this problem and any help given would be greatly appreciated. Thanks

2007-02-03 18:44:58 · 3 answers · asked by ncg 2 in Physics

2007-02-03 18:44:03 · 14 answers · asked by Anonymous in Physics

2007-02-03 18:42:36 · 13 answers · asked by Anonymous in Earth Sciences & Geology

Is the electron configuration the same as N2?
If so can the unshared pair on carbon be neucleophillic?
_
If so can [HCO ]+ be formed?

2007-02-03 18:41:51 · 3 answers · asked by Roy E 4 in Chemistry

2007-02-03 18:40:35 · 6 answers · asked by aida aadzrian 1 in Biology

2007-02-03 18:40:19 · 3 answers · asked by swag711 2 in Biology

2007-02-03 18:37:24 · 1 answers · asked by ssiyamalan 1 in Botany

2007-02-03 18:33:28 · 4 answers · asked by foh_le 1 in Biology

At amusement parks, there is a popular ride where the floor of a rotating cylindrical room falls away, leaving the backs of the riders “plastered” against the wall. Suppose the radius of the room is 3.30 m and the speed of the wall is 10.0 m/s when the floor falls away. (a) How much centripetal force acts on a 55.0-kg rider? (b) What is the minimum coefficient of static friction that must exist between a rider’s back and the wall, if the rider is to remain in place when the floor drops away?
(a) Fc=mv^2/r =(55 kg x (10.0 m/s)^2)/ 3.30m = 1666.67 N

(b) Fc=FMax= usFN = usmg
usmg=mv^2/r
us=(((55kg) (10)^2)/ (3.3))/ (55) (9.8) = 3.09

I really need help on part b. Thanks in advance.

2007-02-03 18:32:15 · 2 answers · asked by ncg 2 in Physics

This is for a science project
please help

2007-02-03 18:27:01 · 6 answers · asked by [Emma.] 1 in Astronomy & Space

2007-02-03 18:26:10 · 6 answers · asked by Anonymous in Biology

I'm thinking about a career as a pharmacist, but what do they actualy do? Like at a hospital or behind the counter at Walgreens (drug store). Do they ground up stuff for pills? Or just perscribe? Or simply fill out orders?

2007-02-03 18:25:42 · 5 answers · asked by Knee 6 in Medicine

2007-02-03 18:21:58 · 12 answers · asked by Anonymous in Earth Sciences & Geology

The question is 2x² + 8x+ 4
My teacher , teach me this formular {ax² +bx+(b/2)²} - (b/2)² +c . But i got stuck. Can anyone help me?Also, can you guys know know the quicker and easier ways to solve??

2007-02-03 18:18:18 · 15 answers · asked by need_need 1 in Mathematics

Ethylene(C2H4) can be prepared by heating hexane (C6H14) at 800 C.

C6H14---> C2H4 + other products

If the percent yield of ethylene production is 42.5 %, what mass of hexane must be reacted to produce 481 g of ethylene?

2007-02-03 18:16:48 · 1 answers · asked by Alan l 1 in Chemistry

Khafre Pyramid in Egypt – a square pyramid Base measurements
Side = 215 m
Height=145 m

Aon Center, Chicago – a rectangular prism (square base)
Base measurements Side = 40 m
Height=345 m
find the surface area and volume of a prism and a pyramid and also the slant height of the pyramid base area from both
I have this results from the pyramid please correct me showing the work thank you'
this what I have :
dimensions of the base 860 m slant height259.326 base area46225 m^2 lateral area 111510.18 m^2 surface area 157735.18 m^2 volume 20783 m^3
I am a little lost with the prism

2007-02-03 18:16:29 · 1 answers · asked by princess 1 in Mathematics

i have like 3 bottles of diffrent types of vitamins.is it bad if i take onr of each a day ,like if it has a side effect or is it ok

2007-02-03 18:14:45 · 5 answers · asked by ♥I_rock_you♥ 5 in Medicine

I have been given two transformers of identical VA and voltage ratings.But one of them is 10 khz transformer and the another is 100 hz transformer. Just by inspection how would u identify which one is the high frequency transformer?

2007-02-03 18:13:05 · 2 answers · asked by rishi 1 in Engineering

2007-02-03 18:11:24 · 15 answers · asked by Anonymous in Zoology

2007-02-03 18:06:51 · 1 answers · asked by Anonymous in Zoology

(a) What is this in meters?
(b) What is this in kilometers?

2007-02-03 18:02:13 · 3 answers · asked by soccerjock 2 in Mathematics