Physics - July 2007

Is getting time back theorically possible? What about wormholes, cosmic stings, white holes and black holes?

2007-07-13 07:08:44 · 13 answers · asked by caltam84 3

at the moment the big bang occurred the universe was infinitely hot. I also seem to remember reading that it was infinitely small. Infinite is not an actual number so is this discrepancy just because you can't really translate the math of the big bang into words? Wouldn't there have to have beeen an actual temperature and size of the universe or is this similar to the lower limit of absolute zero (which actually has a value though)?

2007-07-13 07:04:23 · 5 answers · asked by Herschel Krustofski 2

A 1.5 m long glass tube, closed at one end, is weighted and lowered to the bottom of a fresh-water lake. When the tube is recovered, an indicator mark shows that water rose to within 0.38 m of the closed end. Determine the depth of the lake. Assume constant temperature.

2007-07-13 05:49:29 · 3 answers · asked by makk 3

express periodic impulse delta T = sigma of (delta (t-nT) for n from - to + infinity in terms of exponential Fourier series Cn using exponential Fourier series.

2007-07-13 05:41:18 · 1 answers · asked by 037 G 6

2007-07-13 05:26:12 · 1 answers · asked by gaurav c 1

cooler with the gold side facing the sun or with the silver side facing the sun?

2007-07-13 05:03:51 · 12 answers · asked by Anonymous

First of all, let me say that I already know the answer to this one. I'm asking it just to generate some thought and discussion.

Here's the scenario:

The captain of Spaceship "A" watches as Spaceship "B" flies past at a (constant) speed of 1/2 c. According to the theory of relativity, moving clocks tick slowly; this means the time on Spaceship "B" is passing only 87% as fast as the time on Spaceship "A".

But now look at it from the point of view of the other captain. According to him, his own Spaceship (B) is standing still, while Spaceship "A" is moving at 1/2 c. So Captain "B" believes that Spaceship "A" is the one with the slow clock.

Can each "moving" clock actually be slower than the other ("stationary") clock? If not, are they both "really" ticking at the same speed? If not, which one is "really" slower?

This question is a little like the famous "Twin Paradox," except I've set this one up so that nobody accelerates and nobody changes reference frames.

2007-07-13 05:02:34 · 5 answers · asked by RickB 7

What is the force of electrostatic attraction
beween the plates?

2007-07-13 04:42:02 · 2 answers · asked by Alexander 6

A star before it implodes is a ball of hot gas,
its entropy is huge. After implosion all we have
is mass, angular momentum, and electiric charge.

But according to the 2nd law of
thermodynamics entropy cannot decrease.

2007-07-13 04:38:01 · 4 answers · asked by Alexander 6

Given that an observer is composed of matter, and therefore governed by the same quantum mechanical rules as the object he is observing, what property of the observer causes the wave function to collapse, and a certainty to replace it, once the event in question is observed?
ie, if I toss a coin, and prior to looking at it, it represents a probability function with an equal chance of being heads or tails, what compels it to be heads, or to be tails, when I observe it? For that matter, what mechanism makes the selection 'heads', or 'tails', between two equal probabilities?

2007-07-13 03:39:30 · 10 answers · asked by Ian I 4

2007-07-13 02:18:43 · 13 answers · asked by Anonymous

After turning on the kettle for a few seconds a loud noise starts emitting but looking inside, the water is still. What is making the sound.

2007-07-13 01:40:18 · 3 answers · asked by alissandra v 1

If this actually happened would anyone recognize it as a message from the past? It would not be traveling into the past, but forward into the future and we all travel into the future. What if we in the present send a message into the future, will we ever have our message acknowledged?

2007-07-13 00:40:39 · 6 answers · asked by Anonymous

2007-07-12 23:32:29 · 7 answers · asked by Anonymous

2007-07-12 22:17:07 · 6 answers · asked by smartbiz85 1

2007-07-12 20:48:46 · 8 answers · asked by fozia l 1

I know the formulas for the coefficient of restitution are:

Cr = V(final)/Velocity(initial) and:

Cr = sqrt(bounce height/drop height)

but what is the working for getting to the Cr = sqrt(bounce height/drop height) from using Cr = V(final)/Velocity(initial). I know you have to use PE = mgh and all that.

Thanks

2007-07-12 20:20:51 · 1 answers · asked by Anonymous

Would it be possible, in theory to split a subatomic particle? If so, how much power would it produce? Say if you split an electron, or even smaller than that a quark, neutrino, positron, or other sub-sub-atomic particles, what would one do to even fathom splitting one? If it takes a neutron forced into a large atom to split the atom, would it be possible to fire say, neutrinos or positrons at a proton to split it?

2007-07-12 19:40:36 · 4 answers · asked by ghilliemarine 2

2007-07-12 19:37:00 · 5 answers · asked by greenvillein 1

An inclined plane 10m long has one end raised 10m.If a force of 500N is needed to push a box of weight of 800N ,Find the following...
a. efficiency
b. work input
c. work output
d. Mechanical advantage

2007-07-12 18:50:42 · 3 answers · asked by Boxster 2

hi its me again, i wanted to know how humans see colour, is it when white light shines onto an object then colours absorb and reflect?

2007-07-12 18:37:51 · 7 answers · asked by .............. 1

the new angle between incident and reflected ray is found to be 45. what was the original angle between them?

2007-07-12 18:32:43 · 8 answers · asked by emmy 2

my friend told me that when i jump from a building and falling down is called free fall. but i learned that free fall is falling without air resistance. when i am falling down there is air resistance.
can anyone explain better about free fall to me?

2007-07-12 18:22:07 · 6 answers · asked by Anonymous

2007-07-12 18:16:38 · 1 answers · asked by Goutom B 1

2007-07-12 17:31:24 · 3 answers · asked by Vienna 3

im doing skool project on eyes and there is nowhere on the internet which plainley states what ables us to see... can u help please ?

2007-07-12 16:55:57 · 4 answers · asked by .............. 1

What is this for? what practical uses does it have?

2007-07-12 16:41:17 · 3 answers · asked by Anonymous

Lift=elevator.

2007-07-12 16:40:14 · 8 answers · asked by Chris tf 2

Are there any potential disaster scenarios related to LHC experiments at CERN? If so, how can we avoid the potential apocalypse while increasing our knowledge of particle physics?

2007-07-12 16:39:09 · 3 answers · asked by Anonymous

2007-07-12 16:15:39 · 5 answers · asked by matt k 1