EM field and wave interactions of a point charge
I've been thinking of 2 point charges separated by some distance in static equilibrium. When one charge is moved from rest, the EM field would change the way it looks at the location of the other point...
View ArticleWhy do physics exist? objects interacting ect..?
like how everything bounces off of each other. or collides.. (a pebble dropped onto the sand at the beach for example.. every single particle of sand including the pebble interact with each other.) why...
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What is phase velocity?
According to the wiki page, this diagram: shows the phase velocity and group velocity moving in opposite directions. I think I understand what group velocity is, its the velocity of the overall...
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Inductance of a coil (negative inductance?)
Hi everyone, I encountered a problem as a part of the solution of which I needed to get the i-V relation across a solenoid to gain some intution in the other parts of the problem, which is the well...
View Articlewhat does divergence in the reflectivity mean?
Recently I was reading some paper on design surface plasmon polaritons(so called "SPPs") on corrugated surfaces, mainly these two papers listed below: 1.Pendry, J. B., et al. (2004). "Mimicking surface...
View Articleelectric lines of force
can any one tell me how to calculate the electric lines of force of an arbitrary electric charge configuration ? i have heard that in static case there is no electric field inside a conductor . i now...
View ArticleElectrical Resistance of a Sphere?
How does one find the electrical resistance of a homogenous sphere of uniform density? By connecting two wires across the diameter of the sphere, and assuming Pouillet's Law [tex]R=ρ\frac{L}{A}[/tex]...
View ArticleCalculation of magnetic force on a wire
Hi, I would like to know if it is possible to move a steel wire against frictional forces using a magnet. What would be the approach of calculating the force acting on that thin wire. I would know the...
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Pressure forces from a liquid in rotation
Hi, A liquid in rotation give two kind of forces: 1/ centripetal 2/ pressure forces (Fa, Fb in the drawing) I'm ok that centripetal forces can't give energy (we lost kinetics energy) but Fa/Fb seems in...
View ArticleMagnetic Field of Rotating Charged Cylinder
I read that a rotating charged cylinder would produce a magnetic field as if it were a solenoid. But I thought that the reason that a wire produced a magnetic field was because the electrons were in...
View ArticleRolling of ball
If a ball is given a velocity, and left on horizontal rough floor then after what distance it will stop rollig (slippingis absent) ? Explain with force and torque acting on it .
View Articlerod in freefall
This has been brought up numerous times but I don't really understand it. Consider a rod in freefall. If you put your coordinate frame in the center of mass of the rod, there will be no torque around...
View ArticleVisible light wavelength discrepancy on the EM spectrum?
Hello all, I'm not all too familiar with the electromagnetic spectrum, nor generally with physics but there is something that keeps me up. I learned, and also read now everywhere that visible light (to...
View Articlemeasureing potential of ions
Hi,What is a physical principle of measuring potential on membrane? Or on body,if you measure potential of heart.I know,it sounds,like my question is nonsense.But I know,that voltmeter measure...
View ArticleCalculate light intensity after reflection/refraction
Hi all, I'm playing around with an autocue type of display. So basically, there is an LCD display that reflects light on a piece of plexi, at a 45 degrees angle. I know that the LCD dispay is...
View ArticleProve expansibility / isothermal compressibility
β is expansibility , (1/V)(∂V/∂T) at constant temperature κ is isothermal compressibility , (-1/V)(∂V/∂P) at constant pressure How to prove (∂P/∂T) at constant V = (β/κ) Thank you
View ArticleInternational reference triple point
I know the triple point of water is at 273.16K and atmospheric pressure But how are we going to make it as a reference when we measure temperature of something? Thank you
View ArticlePrinciples of Flight - Heavy aircraft vs Light aircraft
Hey guys, I'm no physicist so thought I'd ask the experts!! A friend asked a question which got me thinking... Question was: why do heavier aircraft take longer to slow down than lighter aircraft? It...
View ArticleIs an imaginary electromagnetic gauge field something physical?
Hi, my question is, if there is an interpretation for electromagnetic gauge fields, whose components are imaginary. This would lead to an imaginary magnetic field... Does anything like this exist? Or...
View ArticleFluid mechanics of fluid inside a ball
I've looked around and I'm unsure about where to start in terms of research with investigating how fluid inside a ball affects the way it collides with a surface... any help? Thanks
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