Physics - December 2006

I emailed the author of lightandmatter.com regarding his textbook Simple Nature. This is an excerpt of my email

""I have an objection to your statement on page 38 bottom paragraph. In reference to the kinetic energy theorom, KE=1/2mv^2 , you state that "what about the factor of 1/2 in front? It comes out to exactly 1/2 by the design of the metric system."

That statement is not accurate since the Kinetic energy equation is fundamentally idependent of the unit system used. Whether we were to use the old english system, the metric system, or any other system the 1/2 would still be required for the equation to hold. I believe you meant that if you were to covert the old English sysetm to the metric system the factor that you stated is required.""

He replied by stating that 1/2 was indeed arbitrary.

Now I know He is 100X smarter than me so if any of you hit his page and read his section of the book tell me What am I getting wrong. Difference of semanantics?What am I missing?

2006-12-28 05:46:29 · 7 answers · asked by David H 1

This question is geared more toward those who have an understanding or strong interest in theoretical physics, ie. atomic, subatomic, particle.

2006-12-28 05:23:41 · 5 answers · asked by Anonymous

I would like to know if free energy devices are possible to build,Which will run forever. Well tesla was first believed to have built such a device,And later on many scientists have also claimed to have built similar devices. So what could be the source of energy behind it

2006-12-28 05:06:43 · 6 answers · asked by mobile_user_01_01_whatever 1

2006-12-28 04:25:20 · 8 answers · asked by Anonymous

I'm 28 and have been reading this theoretical physics book. Since I'm not a student anywhere how can I see protons, electrons and neutrinos? Is there anywhere I can visit to see these experiments performed? I'm hella curious.

2006-12-28 04:16:44 · 4 answers · asked by Anonymous

KE=1/2mv^2 is the equation for kinetic energy. The author of an online physics textbook for scientists/engineers states that the 1/2 constant in the equation is entirely a result of the metric system. That is to say that it is arbitrary. If you were to use another system, say the old English system, the constant would be different.

I believe that the 1/2 is a necessry consequence of the double integration of F=ma from classical mechanics. If by definition f=ma is true, then the 1/2 value for the kinetic must follow regardless of any unit system and is thus not arbitrary.

From my understanding 1/2 in the kinetic energy theorom is dissimilar from say the gravitational constant found in the equation for the universal law of gravitation. The gravitational constant is one of proportionality whose value would change depending on the units used.

Can a chemist or physicist clarify? or anyone else?

2006-12-28 03:45:17 · 8 answers · asked by David H 1

2006-12-28 03:44:45 · 6 answers · asked by fastfredy0 2

Take a 2 liter bottle, stick a nail in the front and back, and fill with about 1/5 salt and 4/5 pure distilled water. Connect the nails to a power source (1.5v to 30,000v depending on the speed you want). Collect the bubbles that come out of the bottle in a cylinder, compress gas until it become a liquid (will become very cold). Place an explosive charge (C4 is best, primer cord is ok) around the cylinder. Attach a metal cup with closed end on one side and ring (like a washer) on the bottom, and fill with hydrazine. Insert this module into a light plastic tube. Mount 3 motors spaced evenly apart at both the top and bottom of tube with wires routed into the tube and up to the top. Mount fins to motors. Connect your receiver unit at top and wire to motors and a camera at top. Place black/clear camera dome to top over camera. Wire primer to last channel remaining and insert into bottom of engine.

2006-12-28 03:40:51 · 9 answers · asked by The Judge G&E 1

In regards to the idea that the universe consists of more than just the 4 dimensions of space and time. If there is at least an additional dimension of space OR time beyond the main 4, then our traditional ideas of a linear beginning or ending to EITHER of them would have to go right out the window, would it??
Yes or No? and why?

2006-12-28 03:12:23 · 4 answers · asked by bradxschuman 6

If I throw it up - why doesn't it stay still while I move at 500mph? Is this the pressurized cabin? If so, what would happen in an unpressurized cabin?

2006-12-28 02:36:00 · 7 answers · asked by GL 2

2006-12-28 02:06:05 · 6 answers · asked by JAMES 4

2006-12-28 01:55:36 · 5 answers · asked by breezinabout 3

2006-12-28 01:50:59 · 21 answers · asked by ? 2

Doesn't this mean that the future is set. You could put it as simply as a tree gets hit with lightning so it catches on fire or as small as the EM wave. And all that sets off a chain reaction. Also doesn't this mean that the speed of light is just the speed of reaction. And that if the speed of light was instant so would all time? I have thought about this for awhile.

2006-12-28 01:44:02 · 8 answers · asked by honor roller 2

See http://en.wikipedia.org/wiki/Michelson-Morley_experiment
Did they fail to include the chemical and physical properties of matter, where the arms "adapt" their length to the properties of the direction, thus maybe causing zero-results that way?
Do the new-to-build gravitational-wave-detectors exclude such influences, causing zero-result answers in the future too?
(I am absolutely no "disbeliever" of Einstein's theories!)
I am aware, that to be able answer this question properly, it needs more than only a few years of university physics.

2006-12-28 01:41:02 · 2 answers · asked by Duliner 4

2006-12-28 01:18:25 · 1 answers · asked by SoMeOnE..... 1

Human interference has created the hole then, why is the hole so far away from humans?

2006-12-28 01:11:21 · 6 answers · asked by Anonymous

2006-12-28 01:02:20 · 6 answers · asked by nocus 2

2006-12-28 00:45:35 · 4 answers · asked by deerdog13 1

2006-12-28 00:41:50 · 7 answers · asked by deerdog13 1

I will soon be beginning my studies towards a Physics Masters Degree and if I wish to continue a PhD. I am curious as to what kind of work I could hope to find. If research, what kind of "employer" seeks a physics researcher? I know teaching is an option but I am most curious about the research aspect of it. Any insight would be helpful. Thank you!

2006-12-28 00:41:20 · 6 answers · asked by Mike 2

What is the difference between an atom and an ion? Ion has net electric charge. So it shows electric property. It acts like a small charged ball. What about an atom? Does it behave as a neutral object?
Atom has equal number of protons and electrons bind together in the space. For this it is said to be electrically neutral. But electric field is a vector quantity, so equal number of positive and negetive charges doesn't essentially cancel out the effect of each other.
Let's take hydrogen atom for example. It has an electron that is orbiting around a proton. At any instance of time, there is a point between this two charged particle that is neutral (according to couloumb's law). But as a whole this system will have net electric property. So a hydrogen atom should behave like a charged object rather than being neutral.
Actually the nature of electric force (static) is such that charges distributed in space (like or unlike), always creates an electric field.

2006-12-27 22:50:19 · 5 answers · asked by Anonymous

Do things (even humans) disappear? How the magnetism of Barmuda Triangle affact on things passes through or above it? What if an asteroid strikes exactly on the Barmuda Triangle?

2006-12-27 22:11:09 · 5 answers · asked by Anonymous

2006-12-27 19:51:14 · 7 answers · asked by Jason B 1

For oscillations: omega^2 x amplitude = acceleration, i thought it should be acceleration=-omega^2xdisplace...
Is displacement always equal to amplitude?
Where is the negative sign and when do we have to take into consideration the negative sign?

I totally cannot understand how the equations are used in the topic oscillations are used and i always fail with 0 marks cause i don't even know what formula to use, can someone please explain to me.

like i saw v=+/- (omega x square root of x0^2-x^2) what is x0?
and why i see another formula for velocity to be -x0sin(omega x t)
where t=time???

what is the difference between x0 and amplitude, i thought they are the same?

HELP, i can't understand and i am suffering from a mental breakdown at the moment.

Please reply fast!!!

2006-12-27 19:31:50 · 4 answers · asked by Anonymous

2006-12-27 19:11:42 · 11 answers · asked by Justanian 1

I'm near sighted, but when I squint my eyes or look through a small hole I see beter. Why is this? Would this be a way of improving eyesight or would the small field of view make it impractical?

2006-12-27 18:43:49 · 12 answers · asked by Robert 2

What causes the magnetic pull to the north?

2006-12-27 18:25:01 · 8 answers · asked by bland46zam 1

2006-12-27 18:20:42 · 9 answers · asked by Ishfaq A 3

Someone asked me to imagine a closed system of pipes of different diameters filled with pingpong balls. There would be a vacuum cleaner installed at some point of the pipeline, and it would both suck and blow the balls, so the balls move in the system.The balls would represent electrons and the amount of balls flowing through pipes would be the current and the difference in pressure would represent the voltage.
I almost got it, but not quite. Santa Clause gave my son an electronic experimenting kit, and now he is asking all kinds of questions which I cannot answer, yet. But maybe with your help I could. Thanks.

2006-12-27 18:17:18 · 6 answers · asked by tm 2