Science & Mathematics - 9 November 2007

In a ground, N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song – one pair immediately after the other. If the total time taken for singing is 28 minutes, what is N?

2007-11-09 04:50:13 · 3 answers · asked by Anonymous in Mathematics

a. the magnetosphere

b. electrostatic repulsion

c. gravity

2007-11-09 04:43:37 · 8 answers · asked by Anonymous in Astronomy & Space

2007-11-09 04:42:04 · 6 answers · asked by Amee 2 in Astronomy & Space

A wooden block with mass 1.85 kg is placed against a compressed spring at the bottom of a slope inclined at an angle of 34.0 degrees (point A). When the spring is released, it projects the block up the incline. At point B, a distance of 6.95 m up the incline from A, the block is moving up the incline at a speed of 7.30 m/s and is no longer in contact with the spring. The coefficient of kinetic friction between the block and incline is mu_k = 0.550. The mass of the spring is negligible.

2007-11-09 04:37:17 · 1 answers · asked by bg 1 in Physics

Okay Im building a mousetrap car/ rat-trap car for my science class. Here are some instructions:
-must move on 4 wheels
-must hold one passenger (have at least one seat)
-minimum size: 25cm length x 20cm width
-maximum size: 30cm length x 25 cm width
-constructed from any household material.
-must be able to to independently cover 4.5 meters.

Please & Thanks

2007-11-09 04:35:55 · 1 answers · asked by Anonymous in Engineering

Hoover Dam was built in the 1930s to provide electricity for the southwest U.S. and to prevent the wild Colorado River from flooding. Hoover Dam is about 380 m wide and is about 221 m high. Assume that Hoover Dam can be approximated by slab geometry with a width of 380 m (W). What is the total force (newtons) on the dam face if the water level from Lake Mead (holding basin for Hoover Dam) is 200 m (D)? Assume the density of water in Lake Mead is 1000 kg/m3.

2007-11-09 04:32:09 · 1 answers · asked by Justin O 2 in Physics

2007-11-09 04:31:49 · 11 answers · asked by Anonymous in Mathematics

http://www.youtube.com/watch?v=A2zKARkpDW4

i saw a documentary on him once, he said he reached 200mph when he reached the atmosphere.

Oh and i am aware of my gaffe of describing it as skydiving when he's doing it from beyond the sky, but space diving sounds crappy

2007-11-09 04:28:58 · 4 answers · asked by IshotJR 2 in Astronomy & Space

My math teacher once told me that someone somewhere was able to prove that 1 + 1 = 3, now this doesn't make any sense to me but what if it someone did prove it? Is it true? Is so who did?...I would ask for the formula but I think it would just be too complicated for my little brain...

2007-11-09 04:27:42 · 6 answers · asked by Anonymous in Mathematics

is the antartic ice sheet expanding or melting this year

2007-11-09 04:25:58 · 11 answers · asked by Russell H 1 in Earth Sciences & Geology

I need this becuse i am planing to go to pluto. (this is just for fun lol)

2007-11-09 04:22:41 · 10 answers · asked by waqaasthebest 2 in Astronomy & Space

im doing a science paper and i need to know how long the sperm can last both inside and outside the body, please only those who know answer

2007-11-09 04:21:19 · 2 answers · asked by Anonymous in Biology

1. Why is the nucleus commonly called the "control center" of a cell
2. What are the two different forms DNA is found in?

2007-11-09 04:15:30 · 3 answers · asked by kewl dude 1 in Biology

Also, is it true the offspring of 2 siblings will be disfunctional? or have a disease of some sort?
Please help. It's for my bio assignment...

2007-11-09 04:14:44 · 11 answers · asked by Anonymous in Biology

2007-11-09 04:11:13 · 3 answers · asked by dude d 1 in Biology

2007-11-09 04:10:10 · 2 answers · asked by beastiegirl 2 in Mathematics

Evolution and eugenics are the dream of the social and illuminati elite

Darwin wrote evolution

his cousin Francis Galton wrote the book on Eugenics

With all their knowledge on cross breeding and inheritance they still decided to interbreed and create supermen

why would he do that with all that knowledge

because its the "Dream" of the social elite

your comments please in particular relating to why someone who knew a lot about Genetics would still decide to interbreed?

2007-11-09 04:08:07 · 2 answers · asked by Anonymous in Biology

I have answered the first 7 questions but I am confused on this one.
Evaluate the indefinite integral (arctan(2x)) / (1+4x^2)

which one do I substitute u for.

2007-11-09 04:06:59 · 4 answers · asked by Smokey. 6 in Mathematics

Can someone help me solve this problem?

Gregg Reid of Atlanta, Georgia, built a motorcycle that is over 4.5 m long and has a mass of 235 kg. The force that holds Reid and his motorcycle in a circular path with a radius of 27.9 m is 1850 N. What is Reid's tangential speed? Assume Reid's mass is 84 kg.

2007-11-09 04:05:11 · 2 answers · asked by Anonymous in Mathematics

Density of concrete is about 1.8-2.3 times that of water (and hence that of victim's body).
http://hypertextbook.com/facts/1999/KatrinaJones.shtml

2007-11-09 04:03:31 · 3 answers · asked by Alexander 6 in Physics

2007-11-09 04:01:42 · 5 answers · asked by mark r 2 in Astronomy & Space

2007-11-09 04:01:37 · 5 answers · asked by IshotJR 2 in Physics

The gravitational pull of the sun on earth is 1 AU so if this is then how much stronger is the gravitational pull on saturn?

2007-11-09 03:59:10 · 5 answers · asked by bluebirdlau 1 in Astronomy & Space

Throughtout millions of years, the human species has been changing and evolving - how can this continue if every time a person is born with an "abnormality", we "fix" it and change ourselves for reasons of vanity?
If we don't let ouselves adapt and evolve, how can the human race survive?

2007-11-09 03:58:42 · 6 answers · asked by lollipop07 2 in Biology

The four sides of a rhombus measures as follows.
138; 180; 155; 197; All in feet--- Can any one work out the area and help me.

2007-11-09 03:55:26 · 3 answers · asked by sunsuk42 1 in Mathematics

2007-11-09 03:53:51 · 6 answers · asked by Anonymous in Mathematics

10x+2y=7
y=-5x+3

2007-11-09 03:53:49 · 3 answers · asked by Boogie 2 in Mathematics

19) what is the critical angle for diamond (n= 2.42)?

20) A diver below the surface of a lake notices that no light appears to be coming toward her greater then the angle theta, measured from the vertical. If the index of refraction of water is 1.33, what is the angle of theta??


please help me and explain this to me, I'm having a hard time, thanks

2007-11-09 03:50:00 · 3 answers · asked by Anonymous in Physics

Okay well I am doing science fair. I have six cosmo plants. I'm going to test which of them grows the tallest. The liquids I will use to grow the plants are Coke, Diet Coke, Vault, Red Bull, & Water. What do you think in the ingredients of these will grow it the tallest?

2007-11-09 03:47:40 · 9 answers · asked by LeightonR 4 in Botany

This is a question my 7th grader has and we have no clue what the answer is please help.

2007-11-09 03:47:30 · 5 answers · asked by czalinsky 1 in Mathematics