Science & Mathematics - 28 October 2007

a person pulls a toboggan for a distance of 35.0 m along the snow with a rope directed 25 degrees above the snow. the tension in the rope is 94.0 N. [A] how much work is done on the toboggan by the tension force? [B] how much work is done if the same tension is directed parallel to the snow?

2007-10-28 17:01:53 · 1 answers · asked by Amy C 1 in Physics

2007-10-28 17:00:09 · 3 answers · asked by Angel 2 in Chemistry

I was in a TA session for math a couple of weeks ago, and my TA was talking about some mathematician's set of numbers that could only be computed by computers in exponential (or was it logarythmic?) time. Because of this, only the first 4 have been found (even though an infinite number exist). Do any of you guys know what I'm talking about?

My TA gave the example of bringing friends to a party or something, but I didn't really follow. Anyone have any insight to what he/I am talking about?

2007-10-28 16:59:58 · 4 answers · asked by AJ B 2 in Mathematics

when is the next solar eclips for the US

2007-10-28 16:58:46 · 2 answers · asked by Furture Mrs. Tootill 1 in Astronomy & Space

my homewrk.
thnxz.

2007-10-28 16:57:52 · 1 answers · asked by Anonymous in Biology

in glasgow,scotland, uk there has been a bright light much bigger and brighter than a star coming out about 3-6am most nights, it stays stationary for about 3-4 hours but moves off when im not looking, it has no hazard lights like a helicopter and floats strangely, has anyone seen anything similar lately?

2007-10-28 16:51:06 · 11 answers · asked by antony s 2 in Astronomy & Space

How did exploration affect the New World?

2007-10-28 16:48:21 · 3 answers · asked by Anonymous in Astronomy & Space

What is the weight in lb.(f) of a 100lb.(m) mass a) when g=32.174 ft/s^2 and b) when g = 31.925ft/s^2

This is how I was told to work it out:

a)
1 lb.(f)= [1lb.(f)s^2/32.174ft.lb.(m)]*[100lb.(m)/1]*[32.174ft/s^2]

=100lb.(f)

I'm confused about the first part of that equation:
(1lb.(f)*s^2)/(32.174ft.lb.(m))
is this just something I should know? How is it derived?

2007-10-28 16:45:18 · 1 answers · asked by Milo 3 in Engineering

2007-10-28 16:42:50 · 3 answers · asked by Anonymous in Biology

I've missed the last 2 lectures for my physics course all I have is a printout of the problem w/o a book to read over. Can someone please answer these questions and provide some feedback as to what/why. Thanks:)

(a) An elevator of mass m moving upward has two forces
acting on it: the upward force of tension, cable and the downward of gravity. When the elevator is accelerating upward, which is greater, T or w?
(b) When the elevator is moving at a constant velocity upward, which is greater, T or w?
(c) When the elevator is moving upward, but the acceleration downward, greater? T or w?
(d) Let the elevator have a mass of 1500 kg and an upward acceleration of 2.5 m/s2. Find T. Is answer consistent with answer to part (a)?
(e) The elevator of part (d) now moves with a constant upward velocity of 10 m/s. Find T. Is your answer consistent with your answer to part (b)?
(f) Having initially moved upward w/a constant velocity, the elevator begins to accelerate downward at 1.5m/s2. Find T

2007-10-28 16:40:42 · 1 answers · asked by Anonymous in Physics

this is the assignment:

find the lateral area of a right triangle prism with a height of 30 centimeters and a right triangular base with a leg of 12 centimeters and the hypotenuse of 13 centimeters


thanks again!

2007-10-28 16:38:28 · 1 answers · asked by Anonymous in Mathematics

In traveling across flat land, you notice a mountain directly in front of you. Its angle of elevation( to the peak) is 3.5 degrees. After you drive13 miles closer to the mountain, the angle of elevation is 9 degrees. Approxiamte the height of the mountain.

2007-10-28 16:36:58 · 3 answers · asked by ladyforensics 1 in Geography

f(x) = (x^3 -1) / (x^3 +1)
I am getting the first derivative as 6(x^2) / (x^3 +1)^2
Need Help with the second derivative. Please Help!!!
Thanks in advance.....
Pleaseeeeeeee explain....

2007-10-28 16:35:43 · 2 answers · asked by Lonely 2 in Mathematics

2007-10-28 16:33:52 · 5 answers · asked by Ronchels N 1 in Geography

any help please! and if you could be so kind as to show work or provide explanations...I WILL ETERNALLY LOVE YOU!

1.) what is the tenth term and the sum of the first ten terms of:
a.) 10, 7, 4, 1, ...
b.) 4, -2, 1, 0.5, ...

2.) what is the infinite sum of: 5, 5/3, 5/9, 5/27, ...?

thank you so much. please help!

2007-10-28 16:32:41 · 3 answers · asked by Answer 2 in Mathematics

http://img3.freeimagehosting.net/image.php?6a6c1a8a03.jpg

Please help me with this problem. Thanks!!

2007-10-28 16:31:56 · 2 answers · asked by dkmu 1 in Mathematics

Where When and Who

2007-10-28 16:27:18 · 3 answers · asked by Mercury 2010 7 in Astronomy & Space

a regular pyramid has a slant heigh of 9 meters. the base is a regular hexagon with sides that measures 4 meters. find the lateral area

help plz.. luv ya!

2007-10-28 16:27:04 · 3 answers · asked by Anonymous in Mathematics

2007-10-28 16:26:29 · 3 answers · asked by Anonymous in Biology

thanks

2007-10-28 16:26:24 · 2 answers · asked by Anonymous in Mathematics

I= - [ 1/x lnx + 1/x ] from e to 7 (this is and integration prob)
turn that into this answer:
I= [(2/e) - (1/7)] (ln7+1)

2007-10-28 16:25:25 · 1 answers · asked by ruby 2 in Mathematics

2007-10-28 16:22:35 · 4 answers · asked by S A M 1 in Physics

Body A of mass M has an original velocity of 6.2 m/s in the +x-direction toward a stationary body (body B) of the same mass. After the collision, body A has velocity components of 1.1 m/s in the +x-direction and 2.1 m/s in the +y-direction. What is the magnitude of body B's velocity after the collision?
________m/s

I tried and got 3 but that is not right.. please explain how to do this!

2007-10-28 16:21:15 · 2 answers · asked by ? 2 in Physics

Douglasite is a mineral with the formula 2 KCl·FeCl2·2 H2O. Calculate the mass percent of douglasite in a 468.4 mg sample if it took 37.20 mL of a 0.1000 M AgNO3 solution to precipitate all of the Cl - as AgCl. Assume the douglasite is the only source of chloride ion.

2007-10-28 16:20:33 · 1 answers · asked by mm 1 in Chemistry

White blood cells manufacture hydrolytic enzymes that function in the intra-cellular digestion of the engulfed bacteria. Describe how each of the following organelles participate in this process: nucleus, rough endoplasmic reticilum, golgi aparatus, lysosomes, and mitochondria. Any help would be greatly appreciated!!

2007-10-28 16:19:40 · 1 answers · asked by burgler09 5 in Biology

I know it was a rerun..(.I'm just tryin' to keep this section alive.)
What did you think of it?

2007-10-28 16:17:59 · 8 answers · asked by Deenie 6 in Paranormal Phenomena

Can anyone help me with this and explain to me the whole procedure and reasoning of it? also what is the difference between pi and sigma bonds?

2007-10-28 16:17:49 · 1 answers · asked by metalmonkey71 1 in Chemistry

It requires two rings of satellites in orbit. The inner ring would be geostationary & transmit its generated energy to a surface relay station, it ability to transmit automatically shut off if it fails to receive the feedback signal from the relay station that tells it it's still properly aligned (wouldn't want a trail of scorched earth if one of them happened to drift off course).

The outer band would consist of copper-bearing satellites set to orbit in the opposite direction and as quickly as possible.

In short, spinning magnetic field + metal surrounding it = electricity. The only way it would possibly run out is if the Earth stopped spinning on its axis, in which event we'd have more than energy needs to worry about.

I call this a "Faraday Belt". Would it work?

2007-10-28 16:17:20 · 4 answers · asked by uncleclover 5 in Physics

5.23 g of hydrazoic acid ( HN3 ) is added to water to make a final solution of 408 ml.
What is the pH of the solution ?

Use Ka = 1.90 x 10-5 at 25.0oC.

2007-10-28 16:16:53 · 1 answers · asked by Nicole G 2 in Chemistry

It gives a definite black streak on a streak plate and possibly has some pyrite inclusions. Can barely be scratched with a steel nail. I don't have the materials to see if it flouresces.

2007-10-28 16:14:08 · 3 answers · asked by For_Gondor! 5 in Earth Sciences & Geology