Transport Definition and 265 Threads

Homework Statement I have a rod of density \rho and length l. It's located at 0\leq x\leq l . The density of internal energy per mass is E = c(T-T_0) + E_0 where T is the tempertature in Kelvin, E_0 is a constant and c is the specific heat capacity. We assume that the temperature is not...

Hi all, Sorry if this is a dumb question, but what exactly do we mean by the term parallel transport? Is it just the physicist's way of saying isometry? Also, in my class we have just defined geodesics, and we're told that having a geodesic curve cis equivalent to demanding that the unit...

Homework Statement I don't even know where to start with this problem Someone please help A sound source sends a sinusoidal sound wave of angular frequency 3000 rad / s and amplitude 12.0 nm through a tube of air. The internal radius of the tube is 2.00 cm. (a) What is the average rate at...

Gyro seems to weird when i think abt it using the transport theorem. i mean for a spinning dish, symmetric one, {Total moments acting on it} = Hdot + w x H --- (1) where H is the angular moment of the dish, w is its angular velocity. then when i consider that it spins inside a box...

Hi Can anyone throw some light on active transport? need urgent help. Thanks in advance

Hi, In papers discussing the physical properties of semiconductors, I have found that they have calculated the piezoelectric coefficient as the ratio between the polarization and the strain in a linear regime (which produces e): a) I think in experiment we first insert an electric field...

Homework Statement I've attached the relevant pictures. The question is: Let X,Y be two containers. At t=0, container X has 100 lt. of water with 2 kg of salt in it and Y has 100 lt. of water with 6 kg of salt. On each t>0, the system transports water as the you can see in the picture...

A vector field is parallel transported along a curve if and only if the the corariant derivative of the vector field along the path is 0. That is \frac{d}{d\lambda} V^\mu + \Gamma^\mu_{\sigma \rho} \frac{dx^\sigma}{d\lambda} V^\rho = 0 This is basically what every book says. But what...

Perhaps someone can clear up some confusion for me. EQs (1) and (2) are synonymous, but use different notations for the derivative. In my textbook, the RTT is written in the following form: Given some fluid property 'B,' let \beta be the intensive property \beta = d\, B/d\, m. Then the rate...

Homework Statement (Last one!) I think I filled out this table correctly, I just want someone to check over it for me, if you would :) Oxygen enters cells by simple diffusion, glucose enters most cells by carrier assisted (facilitated) diffusion, the sodium/potassium pump removes sodium...

Hello, Ok I researched it but I don't understand. What I understand is that when one molecule normally diffuses(high to low) another molecule from a (low to high gradient) attaches to the carrier protein. How does this molecule attach without ATP? I don't get it. Any help would be...

I'm currently enrolled in a course in which we will be modeling parts of a nuclear reactor utilizing Westinghouse ANC code. Here are my questions: My professor said we will be doing coding on Unix-based machines; so, does that mean the ANC code is FORTRAN 90 based? Secondly, when...

A 1.2 ton air conditioner has the capacity to freeze 2400 lb of ice at 0°C in a day. What is the equivalent rate of transport of heat in watts? QH(out)= QL(in) + Wi Coefficient of Performance= QL/ (QH-QL) Coefficient of Performance of an Ideal System: TL/ (TH-TL) QL/QH= TL/TH I...

Homework Statement Hi everyone, I just wanted to double check if I've solved this correctly? Given: \left.\frac{du}{dx} + sin(x)\frac{du}{dy} = 0 \left.-\infty < x < \infty y > 0 \left.u(\frac{\pi}{2} , y ) = y^{2} Solve the PDE Homework Equations Method of characteristics The Attempt...

I want to know how Reynolds Equation of Momentum is accord with the 3rd law of Newton, the law of action-reaction forces. For an ideal fluid, we have that [tex] \frac {\partial m \vec {v}} {\partial t} = \vec v [ \frac {\partial {\rho }} {\partial t} + \nabla [ \rho \vec v ] + \rho [\frac...

In a Stokes theorem, the integral of all curls of a vector field enclosed in some region is equal to the line integral around the boundary. I'm wondering if a similar theorem exists for parallel transport. The Riemann curvature tensor gives a change in a vector when parallel transported...

Say we have a solid wire made of Cu. It seems most electrons transport at the surface of the wire. Right? So is there any difference of the resistance if we have a hollow Cu wire (same diameter with the solid wire). I think the answer shoule be "yes". Right? Becasuse, the resistance R=p*L/A (p...

Homework Statement 2. The attempt at a solution a) The particle seems to be 50 nm in diameter, so D = \frac{k_BT}{6 \pi \eta R} = 4.4E-12 m^2s^{-1} b) j_{diff}=-D\frac{dc}{dx} = -4.4E-12 \cdot \frac{dc}{dx} I don't know what to do next...Can I assume c(x) = c_0x...

I'm a bit confused about parallel transport. We demand that the absolute covariant derivative of our (generalised) coordinates is zero along some curve in some frame. Does this really make our vector stay parallel? What if these coordinates were angles or some other general curvilinear...

Here's my question, friends I have to define initial and boundary condition for a transport PDE: u_t+x(1-x)u_x=0 with x and t is between [0,1], to solve this equation, what kind of numerical method and boundary condition do you recommend and why? What kind of numerical error do you...

Here's my question, friends I have to define initial and boundary condition for a transport PDE: u_t+x(1-x)u_x=0 with x and t is between [0,1], to solve this equation, what kind of numerical method and boundary condition do you recommend and why? What kind of numerical error do you...

Hi dears, I'm following the book of Datta named "Quantum Transport: Atom to Transistor". But just at the beginning, I'm confused a bit;) In the book, at chapter 1, there are some equations given for the current in nanotransistors, for example, an equation for a system with density of...

Hi everybody... i would like to seek help for the problem below. the assumptions I've considered is that transfer is radial only since it is a very long cylinder (infinitely long) that transfer in z direction is negligible, thermal radiation is zero, and wood properties are constant. Starting...

Parallel transport, as one means of quantifying the curvature of a coordinate space, enables changes in a vector's components, when it is carried around variously oriented loops in that space, to be properly measured, i.e. by comparisons made at the same location. Those changes which are...

How do I obtain the Levi-Civita connection from the concept of parallel transport? So Do Carmo asks to prove that for vector fields X, Y on M, and for c(t) an integral curve of X, i.e. c(t_0) = p and X(c(t)) = dc/dt, the covariant derivative of Y along X is the derivative of the parallel...

i posted this also in general physics, but I'm posting it here as well. sorry if I'm breaking the community rules Well this is not my question, but i thought i would ask this in this forum to find a solution regarding the same. Imagine a very long rod that extends between the Earth and...

Well again I'm very new to the field of solid state physics. I understand that phonons are the lattice vibrations which are transferred from one atom to another. In case of harmonic vibration, the phonons are similar to the elastic spring and the atoms are considered like the balls attached to...

Hi, I've been reading these forums for quite a while and now it seems like a good moment for my first post. I'm doing simple coherent transport calculations in tight-binding approximation. The device Hamiltonian matrix H_D is connected to two ideal leads, characterized by the unit cell lead...

Could light be a media for transport? I realize that light is a wave, but isn't also a particle? I mean if air can be used as a media, then why can't light, they are both particles.

Homework Statement Consider a closed curve on a sphere. A tangent vector is parallel transported around the curve. Show that the vector is rotated by an angle which is proportional to the solid angle subtended by the area enclosed in the curve. The Attempt at a Solution First, I parametrize...

I've been trying to figure out how I can start with the Navier-Stokes equation and end up at the Reynolds Transport Theorem. Could anyone provide a link to a derivation of this? or some advice of some sort?

Hi guys, Some background : I'm in the early stages of my first semester of High School Biology and I'm already having some problems coming to terms with the basics. Our original teacher was in car accident over break so we're stuck with a sub, who's a spanish teacher and completely hopeless...

If we have as a manifold euclidian R^2 but expressed in polar coordinates... Do any circle centered at the origin constitute a geodesic? Because I think it parallel transport its own tangent vector.

The parallel transport equation is \frac{d\lambda^{\mu}}{d\tau} = -\Gamma^{\mu}_{\sigma\rho} \frac{dx^{\sigma}}{d\tau} \lambda^{\rho} If I take the derivative of this with respect to tau, and get \frac{d^2\lambda^{\mu}}{d\tau^2} =...

This is something you might want to take a look before you go off on your next air travel in the US. http://www.powerpage.org/2007/12/us_dot_bans_transport_of_spare_lithium_batteries_in_checked_baggage.html This is going to be a bit annoying since we travel with spare camera and camcorder...

http://jalopnik.com/cars/siberian-screwjob/in-russia-zil-screws-you-273231.php The US made one of these but I couldn't find any file footage. The videos are slow to load but do work eventually.

hi guys. I need some basic information about a pump that will be able to transport a nickel slurry up around 1-2m high. the mass flow rate of the slurry is 27 kg/s with a density of 1218 kg/m^3. the temperature of the slurry is 25 deg c. What is the best type of pump to use in this...

Homework Statement Sir i want to design a transport carriage for carrying tea leaf. The carriage will be made of hollow MS pipes which will be fitted on a trolley driven by tractor. The column willbe fitted 2.5 ft apart vertically and parallel to each other along length and breadth. There...

The Reynolds Transport theorem (RTT) is usually applied to derive the conservation of mass, momentum and energy in a fluid. But when I try to apply the RTT to other physical quantities, I get weird results. Can anyone see where I'm going wrong? As a simple example, take the physical...

Hi, I'm working my way through Klimontovich's `statistical mechanics' and I'm having trouble with his derivation of the microscopic transport equation: \frac{\partial N(x,t)}{\partial t} + \mathbf{v} \frac{\partial N}{\partial \mathbf{r}} + \mathbf{F}^M(\mathbf{r},t)\frac{\partial N...

Hi everyone, I am working on a school project and have a question for you all. :) I want to build a modular block that receives, transmites and emites light. http://img292.imageshack.us/img292/8446/untitled1st6.png My main idea is installing a solarpanel/lux receiver just above a room...

i need some help. i am supposed to design a vehicle that is powered only by one standard rubber band to transport an egg to the greatest possible horizontal displacement without breaking the egg. the vehicle can't have any rotating parts. must be constructed from basic parts (ie not...

Hi all! I am confused about the theorem quite much. The theorem says that the time rate of change of a property of a system is equal to the local rate of such property in a control volume plus the efflux of the respective intensive property across its control surface. I am wondering the...

Can anyone hepl me with this?I need some web resource,to start learning from scratch.

need ideas for a contraption that will transport up to 10L of water across a 3 meters on a counter surface. Further Design Considertions: No kits or animals may be used. Propulsion device that you design make must made from simple compoents such as springs, elastics ect. Device may...

Consider a point in space r(vector) where the flux is isotropic; i.e., equal numbers of neutrons move into solid angles d(omega) about every direction omega. a) Show that the net current J(r) is zero b) Show that the magnitude of the current in any direction is just one quarter of the scalar...

hi all! I am not a physics but enginereing major. I am confusing about what's going on with heat tranport in micro- scales. I encounter terms like phonon-electron interaction, electron gas, lattice etc.. What exactly is a phonon? does it posses mass? What is electron gas? Could anyone...

So, I understand in order to evaluate the proper "derivative" of a vector valued function on a curved spacetime manifold, it is necessary to address the fact that the tangent space of the manifold changes as the function moves infinitesimally from one point to another. Therefore, you cannot just...

i don't know where to put this so feel free to move it: I wolud like to discuss ways of Faster than light transport using singularity based forms. (not in reality, only good ways of doing it) thers always the basic one of: ship> }-----------worm hole----------{ but what about...

Why for any material, the number of ion transfers plus electron transfers equal 1?