Physics - July 2007

2007-07-21 05:27:25 · 3 answers · asked by pablo_mcr 1

If I understand it correctly, the "north" pole and the "south" pole are like the ends of magnets, creating the magnetic field. Yet, isnt the core of the earth molten?

2007-07-21 05:14:09 · 4 answers · asked by leikevy 5

Why?

2007-07-21 04:37:44 · 8 answers · asked by Gama 2

Atomic mass=4.00260 u

2007-07-21 04:27:55 · 1 answers · asked by Tam 1

The following is an argument to prove that the direction perpendicular to motion doesnt contract. Is something wrong with the argument? (I know the results are correct) When two rings are at rest with respect to each other (when they are in the same frame of reference), they are exactly the same size. They are in a position similar to the tires on a car axle. Imagine that the rings travel toward each other. If the direction perpindicular to motion contracted then the postulate that all frames of reference are equally valid would be broken because ring 1 would see ring 2 to contract and go inside of ring 1 and ring 2 (because it is at rest in its own frame of reference) would see ring 1 contract go inside of ring 2.

2007-07-21 03:59:48 · 2 answers · asked by jjjjjjjjjjjjjjjj 1

On a cold winter day, the outside temperature is -5.0 degrees C while the interior of a well-insulated garage is maintained at 20.0 degrees C by an electric heater. Assume the walls have a total area of 75 m^2, a thickness of 0.15 m, and a thermal conductivity of 0.042 W (m x C degrees).

2007-07-21 02:53:20 · 1 answers · asked by adrianterrellhogan 1

What is the resistance of electric iron connected to the same source that takes as much current as all three appliances and what is the current through it?

2007-07-21 01:44:37 · 6 answers · asked by minu24suresh 1

discuss the relationship of mechanical advantage of a machine to efficiency.

2007-07-21 01:31:44 · 6 answers · asked by cutejhynxsmile_026 1

If I look at my rear view mirror (night position) during the day, I just see the back seats of my new car (Citroen C3) and not through the tailgate window. But at night, with the mirror in the same position, I do see througth the tailgate window, and the glare from the cars behind is reduced (as should happen I gather). Does anyone know of an online diagram that explains how this works? If not, could you please explain, in layman's language, how it works? Thanks.

2007-07-21 00:55:26 · 4 answers · asked by Anonymous

i've got this question from my prof.
he said he borrowed it from a popular book...
but i just cant find it!!
any help out there???

2007-07-21 00:23:57 · 7 answers · asked by >D_ConTradictor< 4

2007-07-20 23:15:50 · 9 answers · asked by Anonymous

Let me try this again :)
Scientists figured out that making spacecraft 'bluntnosed' helped dissipate the heat on their reentry. So the greater the drag, the less the heat load. Through making the reentry vehicle blunt, the shock wave and heated shock layer were pushed forward, away from the vehicle's outer wall. Since most of the hot gases were not in direct contact with the vehicle, the heat energy would stay in the shocked gas and simply move around the vehicle to later dissipate into the atmosphere.
This still adds heat to the atmosphere.
But does this add less heat than if the spacecraft were more streamlined and therefore less drag or does it create more heat to the atmosphere.
In Other Words, which objects entering the global atmosphere cause the most heat, fatter and blunt or smaller and streamlined.

2007-07-20 23:12:24 · 2 answers · asked by MichelleMcD81 2

2007-07-20 22:09:00 · 13 answers · asked by Human Being 3

Include equations too.

2007-07-20 21:27:33 · 1 answers · asked by Jun 1

water boils at room temp under a vaccum. why not the vaccum of space?

2007-07-20 20:53:01 · 6 answers · asked by jlburchell76 1

2007-07-20 20:37:46 · 3 answers · asked by Anonymous

2007-07-20 19:57:51 · 9 answers · asked by Anonymous

2007-07-20 19:16:15 · 15 answers · asked by daisy_hilo 1

2007-07-20 19:04:12 · 5 answers · asked by Santha Kumari P 1

The lorentz transformations can be (probably invalidly) derived using simple algebra. The idea is to use the postulate that there is no "right" frame of reference, all are equally valid, to show that there is no contraction in the directions perpindicular to motion. Two equal sized (at rest) rings travel towards each other. If contraction occurs perpindicular to direction of motion, one ring becomes smaller and fits inside the other. That ring is at rest in its frame and sees the other ring as contracting and fitting inside of it. Why is that argument flawed (if it is) in proving that the direction perpindicular to motion doesnt contract and is a simple logical algebraic derivation based on that not mathematically sound even if it produces the correct transformations.

2007-07-20 18:04:28 · 2 answers · asked by jjjjjjjjjjjjjjjj 1

2007-07-20 17:57:26 · 8 answers · asked by Anonymous

2007-07-20 17:52:20 · 1 answers · asked by JAMES 4

Can tachyons travel greater than the speed of light? or just at the speed light.

2007-07-20 17:28:14 · 4 answers · asked by jjjjjjjjjjjjjjjj 1

Is it a misconception? Is it already created or exist? Is it plausible?

2007-07-20 17:25:11 · 6 answers · asked by Anonymous

I don't really understand the meaning of this equation.
x = B sin (wt + alpha), where B stands for amplitude.
What is alpha? And for omega, is it just linear speed?

2007-07-20 17:23:42 · 2 answers · asked by Doodle 2

2007-07-20 16:31:50 · 11 answers · asked by JAMES 4

please answer this in a good manner? monday is my physics exam

2007-07-20 16:00:17 · 5 answers · asked by Anonymous

If a rock falls for one second, what is its average speed during that second?

a) Zero ft/s
b) 1 ft/s
c) 4 ft/s
d) 16 ft/s
e) 32 ft/s

2007-07-20 15:35:30 · 7 answers · asked by ? 6

Okay, this has always been bothering me, because whoever I ask I get mixed responses.
Lets suppose you're in an elevator thats free falling from a the
(x) floor. Right before impact, if you were able to jump and get yourself suspended in air, will you avoid getting hurt? Or would you take damage once you land again?

I'm no physics expert nor have I ever really taken a course in physics (-.-) but someone told me about how the velocity at which the elevator is falling is proportional to yours and in order to actually get yourself suspended in air you have to jump at that same velocity or greater. My question here is, is that true?

2007-07-20 15:15:40 · 7 answers · asked by Alex Z 2

Suppose that a complex, lab, or base had 3 levels underwater. They are Level B1, Level B2, and Level B3. Also the only way to get to B2 and B3 is by elevator. That means there are no stairways from B1 leading to B2 and no stairways from B2 leading to B3. Suppose that somehow B2 flooded. Would it be possible to escape by elevator from level B3 to B1 even though the top level B2 is flooded? What would it require to protect the elevator doors from the massive water pressure so that they are not destroyed? Even if the elevator shaft was protected from the water pressure on the outside of B2, could you even still use the elevator to travel back and forth between the dry levels or would it have to be shutdown? And what would B3 look like for anyone down in there, would there be obvious signs that the above level was flooded? I had a dream like this that got me thinking, I must be playing one too many video games!

2007-07-20 14:49:31 · 4 answers · asked by SDG 1