Negative Energy
the potential energy of a earth-satellite system is -U. the kinetic energy of the satellite is K = -U/2. the mechanical energy M = -K. this is not true. the satellite is in equilibrium and the ∂θ...
View ArticleThe equation of the dynamo
I want to know how I can calculate the induced emf in the dynamo, I don't know how I can translate the change of the rotating coil's area into an algebraic equation. Thanks in advance.
View ArticleBungee jumping
I have been doing a research around the physics behind bungeejumping and i need some new ideas. Some of the ideas i already have done are: 1) friction while bungee jumping 2) bunjee jumping (but in...
View ArticleElectric Field of a Conducting Surface
I understand that taking the boundary condition that the electric field changes [itex] \frac{\sigma}{\epsilon_{0}} [/itex] when you cross a charged surface and the fact that the electric field is zero...
View ArticleDielectrics vs. Diamagnetics
So I was thinking about similarities in the nature between these two which could justify similarity in the nomenclature. So, diamagnetic materials are those whose atoms do not have permanent magnetic...
View ArticleGeneration of Static Electricity
I was wondering if and/or how one would could calculate the the generation of static electricity between 2 materials. For example material A is immersed in substance B and moves within it at a constant...
View ArticleOverdamped vs underdamped Langevin
If overdamped equation looks like ##\dot{x}_i=x_{i+1}+x_{i-1}-2x_i-V'(x_i)+F(t)## How to write down the underdamped Langevin equation ##\ddot{x}_i+\gamma\dot{x}_i=\gamma x_{i+1}+\gamma x_{i-1}-2 \gamma...
View ArticleExplanation of the 'chain fountain': some doubts
Apologies if this has been discussed in other threads already. I did a quick search on 'chain fountain' and got no hits. If you coil a length of chain into a container and let it slip out over the lip...
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Problem with energy in a cycle
Hi, I compute sum of energy in a cycle and I don't find 0, could you help me to find the error ? I started an equivalent thread in another physics forum but nobody understand. I hope my english is...
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Dynamics :: Moments - Linear Algebra / Cross Product
Some background: I am self studying dynamics and I have encountered a fundamental problem with either my understanding of linear algebra, or I am just plain dumb. So, I print screened the page of the...
View ArticleMomentum and forces
Hi, I have a question that may be a little silly, but anyway, here is it... From Newton's second law we know that F=dp/dt, this means that, if I apply a force to a body of mass m1 and then I apply the...
View ArticleAcceleration compensation (3 Axis accelerometer)
Hi all, I am currently working on a project and have a problem. I am using a 3 axis accelerometer and attempting to measure distance with it. (Yes, I know, the double integration of doom..) My problem...
View ArticleBack emf and self induction
In the case of self induction, when the intensity increases gradually an emf is induced which generates a back current " equal in magnitude, opposite in direction " to oppose the increase, so if that...
View ArticleCalculating laser fluence -- so confused
Hi, I'm now endeavoring to calculate laser fluence using some laser parameters. The required parameters to solve the fluence are given as: Spot size: 10mm diameter Pulse duration: 200ms Repetition...
View ArticleHow do transformers obey ohm's law??
If you apply 100 volts to a 10:1 transformer you will end up with 10 volts out. If you put a 10 ohm resistor on the secondary you will have one ampere passing through the resistor. That's it !!!' Why...
View ArticleWould modeling collisions using Coulomb forces be useful?
Hi, I am trying to decide on a topic for my senior project, and my professor and I fleetingly discussed my idea of writing a program that models collisions of macroscopic objects using the mutual...
View ArticleIs entropy a measure of "disorder"?
In textbooks I never saw a definition of entropy given in terms of a "measure of disorder", and am wondering where this idea comes from? Clausius defined it as an "equivalent measure of change", but I...
View ArticleTE and TM waves
Could someone please help me understand the physical significance of TE and TM waves?
View ArticleMutual induction
How is the back induced current in the secondary coil transferred to the primary ? I know how mutual induction occurs (and I know that a the bst possible example would be a transformer) but I don't...
View ArticleWhy would the universe be absolute zero lorentz aether was true?
Hi all, I heard of the luminiferrous aether theory ( I know it's disproved I'm not attempting to resuscitate it). I haven't studied it but in one of Paul Davies books he said that "if it existed the...
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