Classical Physics

I was recently reading the definition of the metric unit of force. I have read it before, but this time made the mistake of thinking about it, and realized I don't remember how it was determined.

I see where a black hole can be described by mass, spin and charge. Couldn't another description be the rate of Hawking radiation detected at a standardized distance from the event horizon, or a theorized level occuring at the horizon? Or would that radiation level be a deriviative of the 3 standard discriptions and not independent of them?

Is it possible that matter would be converted to anti-matter in the future? Is anti-matter creation possible in a black hole? We know that the amount of anti-matter created at the beginning of the Universe was small. As the Universe expands we have space-time equations changing. Have such experiments been tried in Laboratory?

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I have kind of an odd question but here it goes. Let's say you have two different headphone pads of different thicknesses, maybe one is half as thick as the other. When wearing the headphones, would the clamping force on each side against your face still be the same, or would there be a different amount of force from each pad because of the different thicknesses?

Imagine you are stood on the back of a train doing 2000mph. You have a gun which fires bullets at 2000 mph. You fire the gun in the opposite direction to the direction of the moving train. What happens to the bullet? Does it simply fall to Earth as the train speeds away at 2000 mph? Does it, at the moment of firing, behave like a normal bullet would fired from a stationary gun and speed away from the fired and momentarily (whilst the gun is fired) stationary gun? Or is there some other answer?

It's been really difficult for me to figure this out. I'm not talking about a sheet of pyrolytic graphic which is immensely strong in one direction (regarding diamagnetic value), rather graphite powder. Imagine putting powdered graphite in a glass of water and putting a strong magnet up against the glass. The force is weak, yes, but the graphite particles are very small -- which also lowers their reaction to magnetic fields. Yet they are also easy to move they are so tiny. I don't understand how these all interact; would a sufficiently powerful (neodymium) magnet be enough to keep the graphite powder from sticking to the glass, or away from the edge? Or is th…

Greetings friends, I have a question about the factors that might account for the continuous variation that can occur in the earth's magnetic field ? How might solar flares induce changes in the magnetic field that covers the earth ? Furthermore, is it possible to detect certain repeated patterns of variation in different geographical locations ? Please do excuse me if the questions might come across as strange, I'm sort of new to this topic. Also, it would be greatly appreciated if you could provide me with the names of a few websites or books that give a general overview or some introductory information about the earth's electromagnetic field.

If a gun is aimed while the barrel is perfectly parallel to the ground and the ground itself is perfectly even, then how is it that the bullet lands where the tiny bit on top of the gun was pointing?

When a man made satellite falls towards earth its energy can be collected by fixing a wind turbine generator above or below it.It is so obvious but how does 2nd law of thermodynamics explain it.

Hi.I would like to ask about which radiations emmited by the cellphones are harmful for the human body and which kind of materials could reflect them. I dont know if I'mposting in the correct type of science,If not just let me know.Thanks in advance.

https://www.facebook.com/383870055097958/videos/605245652960396/ The video is obviously a fake, my guess is that the two black stripes are in fact electromagnets, but frankly I don't really care. What I'm wondering about is, could something like this be constructed, in theory, using a mechanism like this? It goes without saying that it wouldn't display this "periodic" behaviour forever, just apparently so, eventually coming to equilibrium much the same way as a pendulum does (my gut tells me this operates on much the same principle as a pendulum does).

So the formula for Kinetic energy is KE=1/2*a*v^2 Where does the 1/2 come from? And the square is because the work required exponentially increases? KE = work, so that means work = 1/2*a*v^2? Therefore, 1/2*a*v^2= force x distance? Can anyone explain the help relationship?

First of all I acknowledge you that I posted this Question on many other forums and Q&A Websites. So don't be surprised if you found my question somewhere else. I bet when the experts saw the title, many of them said: "...again another dumb guy seeking answers to useless questions...". But believe me I have a point. Let me say I'm not worried if our conversation lead beyond conventional physics and violates or disrupts our standard classical epistemological system of physical concepts. What I want to do is to mathematically and physically clarify the definition of an important concept in physics. Let's get started: "What is energy?" A High school teacher: H…

And one practical one. Hope this is the right place since these are mostly beginner questions. 1. When can we treat objects as point masses/behaving like particles for the sake of simplification of calculations? I ask this question because my physics textbook said that a stiff pig sliding down a slide could be treated as one whereas a tumbleweed could not which I'm not quite sure about. I would think that the pig's limbs and snout jutting out would cause changes in its motion due to the collisions with the slide. Likewise, isn't the tumbleweed a relatively cohesive mass? Maybe if one were to analyze the movement of the tumbleweed itself, I would think it would matter mor…

I assume the hottest temperature the universe has ever contained was at the moment of the big bang. Is this possible to achieve again or beat in the current universe or would it be prevented by entropy? What is our best estimate of the hottest possible temperature?

Hello, Suppose there's a spherical solid of initial radius [math]R[/math]. This solid when dropped in a certain liquid dissolves at the rate [math]r[/math]. By rate of dissolution I mean the loss of the volume of the solid in unit time. By using derivatives, we can represent it as- [math]r=\frac{dV}{dt}=\frac{4\pi}{3}\frac{dR^3}{dt} [/math] where [math]dV[/math] is change in volume, which is directly proportional to the cube of the change in radius of the spherical solid represented as [math]dR^3[/math]. Since the solid moves downward it experiences drag. By Stoke's Law, drag is - [math]F_D=6\pi \mu Rv [/math] where [math]\mu[/math] is the dynamic viscosity of th…

If a pressure is built and contained. That container is awaiting the transfer of it's built up energy, right? Well does the container contain a pressure inside it as the pressure changes on its outside? And supposing that pressure were released into nothing, no matterial anything, and devoid of a resistance of any kind. Would that energy transfer to its contain without a resistant conduit in which to transfer. It seems that Newt's 3rd needs a possitive/resistant bearing source to act as the fulcrum needed to propell the container in the equal and opposite direction of release. Why does this not make sense? Another question( and feel free to move this pne wh…

Hello everyone, As shown in the diagram, there is a semi-circular loop of current carrying wire, such that point P is the centre of the semi-circle and r is the radius. What shall be the magnetic flux density at the centre P? I presume that the diagram must be treated by the Ampere's Law. So, [math] B=\frac{\mu_0 I}{2\pi r}[/math]

Hi, I have this question. Can anyone please explain the answer as I am unwawre of it. A current I1 carrying wire AB is placed near another long wire CD carrying current I2. I1 is perpendicular ti I2. If AB is free to move then it will move : (A) Towards left (B) Towards Right © Upwards (D) Downwards

Hello everybody, The Ampere's Law states that the total [math]B[/math]-field generated by a conducting element of length [math]l[/math] is directly proportional to the current element [math]I[/math]. Thus, [math] Bl = \mu_0 I[/math] Where [math]\mu_0[/math] is the constant of proportionality. But, will the constant of proportionality be [math]\mu_0[/math] or [math] \mu_0 \mu_r [/math] ? These two sites use two different formulations..... http://www.electrical4u.com/biot-savart-law/ http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html#c1

is there any known link of superconductivity to virtual particle behavior? Would the exclusion of virtual particles tend to reduce the "noise" in the system if that were possible? If not, would it be possible to exclude the particles from a given region under any condition ?

is there a plank-time corrected "scientific second", with a multiple of the plank-time minimum as standard?

Is there a theoretical smallest physical disturbance that would cause a wave to occur? Would it be possible to create a wave with an electrical or electomagnetic stimulus?

Its really WoW that our observable world is a World of Wave. Almost all kinds of energy transfer takes place through wave motion. Sound travels in the form of waves through a medium. Light too travels as EM waves. Even pendulum, AC current, simple spring motion are found to be composed of periodic wave motion. This makes me ask why is wave motion so dominant over others? Any thoughts?