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damped harmonic oscillator
Hi, in this article: http://dx.doi.org/10.1016/S0021-9991(03)00308-5 damped molecular dynamics is used as a minimization scheme. In formula No. 9 the author gives an estimator for the optimal damping...
View ArticleEffect of magnetic materials on field created by current
Hello, Imagine I have an infinite wire with a DC current. Around it there two rings of ferro-magnetic material, not far from each other. Does changing the mu_r of one of the first ring, changes the...
View ArticleAction-reaction pairs, concerning gravitational force &normal reaction
I would like to know how it is possible that I can be at rest on the surface of the Earth (relative the the earth of course). My main cause for confusion is the action reaction pair that occurs when I...
View ArticleRolling Down Ramp - Question on Friction
You have a cylinder rolling down a ramp, without slipping. There is a rope wrapped around it (pulling up) with tension T. The direction of friction is always up the ramp. How do I picture this? From...
View ArticleVan der waal's equation and resulting curve
So as per van der waal's equation, below critical temperature, for each pressure and temperature, we have only 3 possible volumes for each pressure-temperature pair. My questions are as follows: 1. So...
View ArticleWould wind tubine on moving automobile pomote inlet efficiency ???
Question as the title above ! Could we use the wind turbine to compress the air into engine cylinder as the exhaust compression tubine does ? Thanks all for replying !
View ArticleThe direction of R
Dear friends, and science lovers, I am doing some statics problems with moment( cross-product).And I've been having some problems solving them.I am getting the result but in opposite sign. I mean I...
View ArticleUsing Fluid mechanics to rate power output of an engine.
I trying to come up with a way to measure the power output of an engine using a water pump, And I wanted some one to go over my math and check for flaws in my thoughts. My idea is to measure the flow...
View ArticleElectric far field for an arbitrary current through arbitrary antenna
If we consider an arbitrary time varying current [itex]I\left(t\right)[/itex] flowing through an arbitrary antenna, then is the following a plausible expression for the electric field...
View ArticleBasic momentum question
If a person jumps off of a boat with constant velocity, should the equation resulting from the law of conservation of momentum be (where 1 denotes the mass/velocity of the person, 2 denotes those of...
View ArticleMechanics Problem (Tension)
Recently stumbled on this problem: A uniform disk (I =½ MR2 ) of mass 8.0 kg can rotate without friction on a fixed axis. A string is wrapped around its circumference and is attached to a 6.0 kg mass....
View ArticleBraking Formulas for Heavy Trucks
I am working on virtual modeling, simulation & analysis of Heavy Trucks with Adams/truck. I need to check the Braking distance at Emergency Braking , I found some results from my simulation , Now I...
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Projectile Trajectory - as influenced by multiple factors
Hello All, I'm currently working through a scenario in which the following occurs :An object of mass M1 (kg) approaches a rotating wheel at a speed of S1 (m/s) along a belt The belt is at an angle Th1...
View ArticleBack Emf Paradox
Correct me if I am wrong. For a RL circuit, I know as a fact at t=0, there is a back emf that is almost equivalent to the original emf source. In order for the back emf to exist, there needs to be a...
View ArticleAcceleration as derivate of velocity
I have problem understanding the following derivation: a = dv/dt v= ds/dt (i get this part) but then, a = (dv/ds)(ds/dt) I can't understand the above equation? Please can you tell me how 'a' gets that...
View Articleelectron gas oscillations
Consider a slab infinite in x,y direction but very thin in z direction. As a classical model assume that we displace the electron gas surrounding the static iron cores slightly. With this picture, does...
View ArticleIs there an algorithmic way of drawing phase portraits by hand?
I have trouble understanding how to draw phase portraits. Is there a good pedagogical overview of their basics (such as elliptical vs hyperbolic orbits, separatrices etc.), along with an algorithmic...
View ArticleHuman slingshot
I want to build a fun, but potentially dangerous toy - a human slingshot (into a lake). I'm trying to figure out the physics of a contraption like this but it's been 20 years since I took a physics...
View ArticleSwinging periods of physical and simple pendelums
Hey! Where is the error in my reasoning?: The acceleration of the centre of mass in a swinging physical pendulum in simple harmonic motion is given by: ##M \ddot{\vec{r_{cm}}} = \sum m_j...
View ArticleR.Fizpatricks' problem from his online "Lectures on CM"
In those "Lectures on classical mechanics" in problem 2.4. for 'Newtonian mechanics' section the author gets the expression for angular frequency of small oscialations as the square root from the ratio...
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