Varying thermal conductivity with length
I'm interested in modeling a system where the material varies along its length, thus the conductivity coefficient would be a function of both T, and x. k(T,x). For starters, if I assume negligible...
View ArticleLumped tire model : bristle deflection
Hi, And thank you for your time! :) I've been studying and coding for more than a month on a physic engine for car driving simulation. Right now, I'm trying to change the whole tire model currently...
View ArticleDoes friction slow down a wave (in a phone cord among others)?
I'll pose that as a general question, and specifically for sound waves, which Googling did not answer in a satisfactory way. And a specific instance I'm concerned with is as follows: - Students are...
View ArticleHigh Repetitive Photocathode RF Gun
Hi fellows, I've been looking for "High Repetitive Photocathode RF Guns" for more than a couple of days. It seems, first I need to understand the RF Guns. I deciced to search such a document that gives...
View ArticleThermodynamics without partition function
Is there a way to derive entropy or free energy without using partition function?
View Articleelectricity formula
Hi I want to know what is the diffrences between E=σ/2ε0 & E=σ/ε0 of course I know we use the first for a very huge page but what about the second formula? I saw in some solving of question when we...
View ArticleClassical, electrons fall into nucleus, why not planets into sun?
How is electromagnetism different from gravity in that accelerated objects radiate EM waves when accelerated in an electric field but no gravitational waves are generated when objects are accelerated...
View ArticleMagnetic Monopole (Magnetic Charge)
An electric charge produces a Coulomb electric field: E = dqe r/r3 A current element produces a Biot-Savart magnetic field B = i dl×r /r3 From what I understand, magnetic charges are inserted for the...
View ArticleElectric fields vs magnetic fields???
Ok, so in class last week, I had asked my professor about using the Lorentz Force Law to solve a particular problem. When he responded with "we only have a magnetic force from the current in the wire,...
View Articlethe electric displacement vector field and Gauss' law?
Hi, I know that for the electric displacement vector field [itex]\oint D.dS[/itex]=[itex]\sum Q_{c}[/itex] does this mean that I can just use a Gaussian surface to explain why the displacement vector...
View ArticleKepler's 3rd (multiple)
Hi, I am doing a physics project at school, which consists of recreating our solar system (with the sun and only 2 planets, Earth and Jupiter) with Visual Python. Then we want to measure the speed...
View Articletranslational/applied forces
Lets say I have a horizontal rod whose total length = ΔXtotal = 5 inches. However, the rod is made up of two pieces (ΔXshaft = 4 inches and ΔXbase = 1 inch) that are welded together, where ΔXtotal =...
View ArticleField lines from a line of charge
I have a general gauss' law/electric field question. In calculating the electric field of a cylindrical shape, gauss' law can be applied to find that the Electric field only points aways from the...
View ArticleAcoustic levitation shape question (Japanese scientists link)
http://sploid.gizmodo.com/amazing-sc...usi-1492880964 http://www.youtube.com/watch?v=odJxJRAxdFU I wanted to ask is there a specific reason for the completely horizontal X shape of the levitated...
View ArticleQuestion about u and h and Its Differential Changes for Ideal Gases
Hello 1. I was wondering why internal energy is usually expressed as a function of temperature and specific volume and enthalpy a function of temperature and pressure (ie why is u(T,v) and h(T,p)) and...
View ArticleReflection of sound. Changes to its properties.
Hi guys and girls, Just had a question I have been thinking about for a while. Suppose you have a sound maker than makes a pure tone at a particular frequency. You play this tone for an instant...
View ArticleCalculating Cd and Crr coefficient experimentally
On this site I found how to calculate Cd and Crr coefficient from experimantal data: http://www.instructables.com/id/Meas...t-of-your-car/ I am trying to implement it in a web page and in a smartphone...
View ArticleMeasuring time delay before charged plates repel
Imagine two parallel conducting plates set at a distance of several meters. If one charges the two plates simultaneously then one would expect a small delay before they started repelling each other due...
View ArticleCalculus of variation
If for some functional ##I##, ##\delta I=0## where ##\delta## is symbol for variation functional has extremum. For ##\delta^2 I>0## it is minimum, and for ##\delta^2 I<0## it is maximum. What if...
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