diffusion on liquid
Hello. I know what is diffusion... chemical process when molecules from a material move from an area of high concentration to an area of low concentration... Typical example is ink in water. However,...
View ArticlePoynting's theorem and escaping particles
I was thinking the other day and it looks like I need feedback if I am being stupid or crazy. My question is quite simple - does Poynting's theorem cover the situation of charged particles escaping...
View ArticleGreen's First Identity involving Electric Potential
I am attempting to work through a paper that involves some slightly unfamiliar vector calculus, as well as many omitted steps. It begins with the potential energy due to an electric field, familiarly...
View ArticleRole of Pipe Length in Poiseuille's Law
I can't figure out why the length the a pipe (L) increases the change in driving pressure with respect to this law: Delta P = (8*mu*L*Q)/(pi*(r^4)) I would think that delta P wouldn't change because...
View ArticleElectromagnetism and Clean Energy
Hey, currently I am a high school graduate going into college in the fall, but that isn't why I am here. There has been this question eating at the back of my head. Is there some way to induce an...
View ArticleHeat flow
If heat flow is the momentum change from a faster moving atom or molecule to a slower moving one, and momentum is mass x velocity is it possible - for a very limited amount - for heat to flow from a...
View Articlegravity vs inertia
As it's stated in Newton's law of gravitation, every object with mass attracts all other object with a force which causes acceleration. So basically there are infinite number of forces in our universe...
View ArticlePower for a blackbody radiation
If a blackbody is in equilibrium with the surrounding electromagnetic field, the power emitted by the surface of the blackbody will be related to the energy density of the electromagnetic field by...
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The Force of Impact on Water
I really want to know if there is a difference between the force from the first impact of water and the force from water resistance. If it is different can someone tell me a explanation on why it is...
View ArticleTangential acceleration in circular motion
We know that the magnitude of tangential component of acceleration is, atangential = dv/dt (where v is speed) So clearly atan = 0 for uniform circular motion (as v is constant) But what about...
View ArticleDifficulty understanding EMF due to a changing magnetic flux
Hello everybody, I'm studying classical electrodynamics and I'm having a difficulty grasping the concept of EMF. I'll try to explain what causes my confusion. Say I've got a conducting loop, an...
View ArticleAir heavier than water? Will it sink?
The seawater in deep oceans have a density of 1050 kg/m³ or so. The density of air is about 1.3 kg/m³, about 800 times less. If air is compressed to a density higher than the water in deep oceans and...
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Why is dr/dt= -V
In the solution , it says we have dr/dt= -V (polar coordinates) How? i can't see how this can be possible , we know that r(t)=V/w(t), and that's it .
View ArticleThick Pinhole and Spot size
Didn't seem to have much luck on the actual reasoning with this elsewhere. A regular pinhole projects an image, and has a diffraction limit for the image, that is the size of the airy disk. What if we...
View ArticleBrownian Ratchet
In feynman's description for the ratchet pawl system he gets the efficiency for the system to be same as he efficiency in the carnot cycle. I am not able to understand or if its correct that the...
View ArticleGravitational acceleration towards and through an object
Take a hypothetical object with an infinite density (purely so that a particle can get incredibly close to it). Furthermore imagine that this object has no close range repulsive force, or in other...
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Is stress tensor symmetric in Navier-Stokes Equation?
Hello, In CFD computation of the Navier-Stokes Equation, is stress tensor assumed to be symmetric? We know that in NS equation only linear momentum is considered, and the general form of NS equation...
View ArticleDynamics of a system of particles all influencing eachother
Take a closed system of particles. Each has it's own mass, but that's really about it for the sakes of this argument. Now suppose there is some standard force law that applies between particles,...
View Articleproblem understanding newton's III law
I have problem undestanding newton's III law. When i press the wall the wall react with the same force on me but as I have less mass I have greater acceleration so I am moving away from wall. When I...
View Articleliouville integrability
Hi Let a classical particle with unit mass subjected to a radial potential V and moving in a plane. The Hamiltonian is written using polar coordinates [itex](r,\phi)[/itex] [itex]H(r,\phi) =...
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