Science & Mathematics - 24 September 2007

That is what internal mechanisms initially suck so much current out of the wire that other devices blink and then seemingly require very little energy once they have reched top speed? What about the machine changes when it tansitions from using 6x the operating current to only one times the operating current?

Is it simply a matter of the resistance decreasing as soon as the motor attains its desired speed?

Thanks a lot.

2007-09-24 07:23:03 · 5 answers · asked by wonderer 1 in Engineering

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2 Questions about the Earth?

Is the Earth the only planet with an ocean? And can you name three ways to assess that the Earth is round? I've read like hell to find out the first one and the book doesn't really give an answer to the second one. That one seems to be a common sense question that I must not have the sense to figure out. Maybe I'm thinking too much.

2007-09-24 07:12:04 · 4 answers · asked by Anonymous in Other - Science

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A 5kg rock is thrown upward with a force of 150N at a location where the local gravitational acceleration is..

9.79m/s^2. Determine the acceleration of the rock in m/s^2

2007-09-24 07:08:01 · 1 answers · asked by s4_orce 1 in Physics

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Convert the following into grams. 345,000ng 34,981ug and 0.7824 mg?

2007-09-24 07:03:29 · 9 answers · asked by Anonymous in Chemistry

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write this in binomial form: 20x2 + 13x + 2?

the 2 is x to the 2nd power

2007-09-24 07:02:20 · 2 answers · asked by hawaii 1 in Mathematics

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As a casual observer, how might I distinguish between chalcedony and moonstone?

They seem quite similar when I shop at craft fairs.

2007-09-24 07:02:09 · 2 answers · asked by Anonymous in Earth Sciences & Geology

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The point at which the continent stops and the rock of the ocean floor begins is the called the continental?

A.drift.
B. shelf.
C. divide. D. slope

2007-09-24 07:01:32 · 7 answers · asked by LaKeshia H 1 in Geography

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what does this mean? what soes it want me to do?

the question says:
Compare the momentum of a 50-kg-dolphin swimming at 10.4 m/s and a 6,300-kg-elephant walking 0.11 m/s.

so what do i do? what kinda answer are they looking for? im just so confused physics is so not my forte!

2007-09-24 07:01:26 · 2 answers · asked by Anonymous in Physics

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How do you solve 4x^4 - 65x^2 + 16 with all the possible solutions. I tried graphing it, but don't know how

to get the solution from the graph

2007-09-24 07:01:22 · 3 answers · asked by Dalila 1 in Mathematics

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Accounting Homework?

What is the payment each year I will have to make if I want to have $70,000 at the end of 8 years. Interest is compounded annually at 8%

2007-09-24 07:01:04 · 2 answers · asked by Saw 3 in Mathematics

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Is this right?

Im trying to figure out an estimate of how much money I've spent on gas for my truck since I got it. I have put 44,000 miles on it at $50 a fill up (worst case estimate) and I get about 320 miles on a full tank. The answer I got was $6,875. I was wondering if some of you could help me out and tell me if that is what you figured because $6,875 seems too less than what I was guessing. Thanks.

2007-09-24 06:59:36 · 3 answers · asked by Anonymous in Other - Science

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Universal sets?

For the universal set U - {0,1,2,3,4,5,6,7} and the sets A= {1,5}, B = {1,2,3,4} and C={4,6}, list the elements in the following sets.

a. A "union" <-- ( should be an upside down U shape) B
b. A U B'
c. A (upside down U) (B U C)

2007-09-24 06:57:06 · 1 answers · asked by PhysicsDummy 2 in Physics

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Please Help! 10 points?

1. What evidence did Alfred Wegener use to support his theory of continental drift? (Points: 1)
Wegener´s only evidence was that coastlines between continents fit together like puzzle pieces.

Coastlines fit together between different continents, and similar rocks and fossils are found on different continents.

Wegener had no evidence, which is why his theory was rejected.

2. In a convection cell, cold dense material rises, while hot, less dense material sinks. (Points: 1)
True

False

3. What is the name for the supercontinent that once formed from all the continents? (Points: 1)
Gondwanaland

Laurasia

Pangaea

4. Plates move on top of which layer of the earth? (Points: 1)
asthenosphere

crust

core

5. What is the source of earth’s internal heat? (Points: 1)
only radioactivity

only heat left from earth´s formation

both radioactivity and heat from

2007-09-24 06:49:41 · 5 answers · asked by JJ 1 in Earth Sciences & Geology

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what are the three major rock types are present in the rock cycle?

2007-09-24 06:44:39 · 12 answers · asked by Anonymous in Earth Sciences & Geology

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The world's end? - December 21st, 2012?

Does anyone know anything about this? I just learned about the rumor today, but despite all my google searches I come up with no conclusive "evidence" besides "The Mayan calendar ended on that day." (Well, my calendar ends Dec 31st of this year. Then I go out and buy a new one. Doesn't mean the world is over, yeesh. O_O) Seriously, this interests me. Is there anything that could seriously contribute to the end of the world in 2012, or is it a big bunch of supersitious hoo-haw like the Y2K crisis?

2007-09-24 06:42:27 · 15 answers · asked by paddingtonruxpin 2 in Astronomy & Space

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Organelles of a Epithelial cell in a small intestine.?

Can anyone tell me if a small intestine epithelial cell from the small intestine has any of the following organelles: golgi apparatus, mitochondrion, nuclear envelope, plasmid or ribosomes. Thanks!

2007-09-24 06:41:29 · 3 answers · asked by topher 2 in Biology

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How is iron turned into steel?

2007-09-24 06:40:46 · 6 answers · asked by Anonymous in Engineering

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You are given that x=4?

You are given that x=4
Find values of:

(2x^-4)^3 * (x^4)^2

2007-09-24 06:40:18 · 6 answers · asked by Anonymous in Mathematics

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What are the magnitude and direction of the net gravitational forces acting on each of the three particles?

The drawing shows three particles far away from any other objects and located on a straight line. The masses of these particles are mA = 363 kg, mB = 517 kg, and mC = 154 kg. Find the magnitude and direction of the net gravitational force acting on each of the three particles (let the direction to the right be positive).

http://i240.photobucket.com/albums/ff278/mysterypenguin12/111-1.gif

2007-09-24 06:39:03 · 1 answers · asked by mysterypenguin12 1 in Physics

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is a stick if dynamite explodes a chemical or physical reaction?

2007-09-24 06:38:29 · 5 answers · asked by veondra r 1 in Chemistry

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The gently sloping shallow area that extends from the continental shore is the called the continental?

A. drift
B. divide
C. shelf.
D. slope.

2007-09-24 06:38:12 · 4 answers · asked by LaKeshia H 1 in Geography

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Could Argentina be considered the country with the largest quantity of penguins?

They live all along the Patagonian coast, so it must be.

Also, does Chile and New Zealand have penguins?

And, does Walruses exists on the south pole?

2007-09-24 06:37:54 · 2 answers · asked by Philidor 5 in Zoology

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help with coefficients!?

Determine the equation of each line. Write the answers in standard form using only the integers as the coefficients.

1) The line through (-2,0) with slope of -3/4

2) The line through (-2,4) that is perpendicular to the x-axis.

Please show work and explanation. I really appreciate it!!! Thank you!

2007-09-24 06:34:49 · 5 answers · asked by Vonnie 2 in Mathematics