Solenoid filled with magnetic material
Consider a solenoid with length L and N turns of wire wound around it, filled with a rod of permeability [itex] \mu [/itex].I wanna calculate the magnetic field it produces on a point P on its axis and...
View ArticleOptical misalignment
Hi all I was just wondering if anyone could help me with estimating error caused by misalignment of an optical arrangement. I am interested in how the focal length of this arrangement will be affected...
View ArticleSingle slit diffraction
I've read that if you want light to diffract through a single slit, the slit opening must be equal too or less than the wavelength of the light. So for example, light of wavelength 600nm would diffract...
View ArticleSmallest Difference in Wavelength the Human Eye Can Notice
Hello - I'm having a difficult time finding this answer anywhere else on Physics Forums. I'm curious if anyone knows, or can figure out, the smallest difference in wavelength that the human eye can...
View ArticleWhat is the use for plasma pressure?
Hi! I just wonder what's the actual use for [tex]p=nkT≈nE_k[J/m^3][/tex] when it comes to plasma physics? What does p help us understand/enable? While Ek is related to particle velocity and thus...
View ArticleAverage kinetic energy of a damped oscillator
For a damped mechanical oscillator, the energy of the system is given by $$E = \frac{1}{2}m \dot{x}^2 + \frac{1}{2}k x^2$$ where ##k## is the spring constant. From there, I've seen it dictated that the...
View ArticleA question about damped resonant frequency!
The standard equation for the damped angular frequency of a normal damped mass-spring system is ω[itex]_{d}[/itex] = [itex]\sqrt{\frac{k}{m}-\frac{b^{2}}{4m^{2}}}[/itex]. Let...
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A question about resonance curve!
Searching through Wikipedia (http://en.wikipedia.org/wiki/File:Resonance.PNG), I found this graph about resonance. I do notice from the graph that as the driving frequency gets closer to the natural...
View ArticleSeparation of Variables
I am studying Laplace's equation in my electrodynamics course (using griffiths intro to electrodynamics). I am watching a youtube video stepping through the separation of variables method for solving...
View ArticleEM waves and forces
Would a particle kept in the path of an electromagnetic wave experience a force? Both magnetic and electric field are present, so the equation of motion may be complex, but i have never seen my...
View Articleoptic prototype manufacturing
Hello, I am a college student. Recently, theoritically, I have been working on new design of diffractive optic element, Now I want to test it in real life and see if it is really working (practically)...
View Articlegauss's law question
Suppose you have a sphere (sphere A) with net positive charge 2Q. A conducting spherical shell (sphere B) of inner radius b and outer radius c is concentric with the solid sphere and carries a net...
View ArticleSign problem with potential
I've been having a problem with the sign of potential. Electric potential as I know it is defined as V = -[itex]\int_{C}\vec{E}\bullet\vec{dl}[/itex] where C is the path from a location defined as zero...
View ArticleProgramming the forces the sun applies on earth
Hey guys, I am trying to create a 2d simulation of the earth going around the sun. However I am facing an issue. I am not sure what are the forces that apply on the earth in a 2d aspect. I know there...
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Moving magnet and conductor - Residual worry
This is about a famous thought experiment, cited by Einstein at the beginning of his first 1905 paper on SR, and discussed in textbooks and on this forum. I've fleshed it out with a specific set up,...
View ArticleWhere does this energy go?
Say, i have two concentric shells,each carrying a different charge.If i connect an ideal, resistance less wire between the two, charges will flow till potential of the two shells is equal.For an...
View ArticleQuestion regarding systems in work & energy
My professor (for some weird reasons) makes us write "system [body(ies)]" whenever we are asked to solve a physics problem for work and energy. Systems make me completely confused because sometimes if...
View Articlestrange claims about heat transfer
I'm trying to evaluate floor heating systems for installation in my new studio, and I have to admit that my thermodynamics is a bit rusty... But I came across the following, and I could use a...
View ArticleCalculating the effectiveness of a Radiator and Fan Combination
Hello, I am trying to compare different combinations of Radiators and fans on their ability to cool water(or any liquid for that matter) Now I've been showen some Bernoulli's equation things and been...
View ArticleCompression of air entrained in water
Hello! I am wondering what supplies the energy necessary for the compression of a gas that is entrained in a flow of water. For example: 1. a water/air mix is traveling down a horizontal pipe with some...
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