Diagrams Definition and 659 Threads

Homework Statement Determine if the following diagrams may describe an electrostatic field in a charge-free space. The rectangles are the spaces under consideration. In the first four diagrams there are field lines while in the last two there are equipotential lines Homework Equations...

I'm trying to write a very simple program to generate shear and bending moment diagrams for beams. The thing is that I don't know what kind of loading that the beam may see so I want to be able to write it as generically as possible. I'm trying to find a web resource (not a book, unless...

1. Homework Statement [/b] Consider the dynamical system \frac{dx}{dt}=rx-\frac{x}{1+x} where r>0 Draw the bifurcation diagram for this system. Homework Equations The Attempt at a Solution Well fixed points occur at x=0,\frac{1}{r}-1 and x=0 is stable for 0<r<1 and unstable for...

Hi, When looking at a photo or sketch, I find it hard to take out the important bits and turn it into a freebody diagram. I am doing this question (pic attached). Im quite unsure how to even begin. I've though of a few ways to start analysing it. The first way analyses AD as a whole. And...

Homework Statement Fill in the missing quantity for the following: V = constant FNet = ? a = ? F1 = ?Homework Equations FNet = Fn - Fg + Fa - FF Fg = mg FNet = maThe Attempt at a Solution Because I honestly do not know how to go about solving this, the only things I've done are review class...

Hello All, I was wondering if anyone can help me interpret these wiring schematics. As some know, I am trying to use a stepper motor to generate power. The motor can be wired in both unipolar and bipolar configurations. From my research, it seems to get the most power a Bipolar configuration...

Dear collegues, I want to share with you a little idea which permits to obtain (almost apparently) renormalizable Feynman diagrams for General Relativity. (See attached file) This idea exchanges renormalizability with non-locality. I'll vary fain if someone of you will try to calculate any...

PROBLEM 1 Homework Statement A block of mass m = 12.5 kg rests on an inclined plane with a coefficient of static friction of μs = 0.08 between the block and the plane. The inclined plane is L = 4.5 m long and it has a height of h = 3.25 m at its tallest point. m = 12.5 kg μs = 0.08 L = 4.5 m...

This is an attempt to solve the twin paradox via two Minkowski diagrams with a few questions attached. Note that there might be mistakes in this drawing i will fix in the course of this thread in case someone notices any. First, let me explain the two Minkowski diagrams in the drawing first...

Hi, this isn't really a homework problem... but I'm just wondering I see the time axis as c*t, now people say that its to scale the time axis so that the world line of light is 45 degrees. But if you were to multiply time by the speed of light, wouldn't you just get the units metres or...

Hello All, I am interpreting a diagram from the following question. (I didnt have a chance to take thermo and I learned it by myself so I might have some problems) http://www.physicsgrad.com/pgre/9677-15 I understand that I can just do ΔW and I get the right answer, but upon doing it...

Hello, I have the following problem part (b) which I already solved as you can see in the attached image. So I am not asking homework questions, I merely reviewing my homework for a better understanding for the test. I obtained the answer from a friend showing me his method. However, I am...

Homework Statement The picture attached is the problem. Also given is the constant acceleration of 2m/s^2, a frictional force of 75N, and the mass of block A is 25kg. Homework Equations The Attempt at a Solution I just need help with drawing the free diagram part involving the normal force...

Ok this will be a long post, sorry in advance. I am an online student of a university and the help I am getting from them is ridiculous, I am also using a book called quicksmart introductory physics, and for the most part it is quite rubbish. 1st Problem: (not homework questions, I am trying...

Homework Statement Assume the system is massless. The Attempt at a Solution Here is my quick attempt at drawing a free body diagram for this system: What I am not sure about is the direction of the force at F. Should the force be A or B?

Homework Statement http://img189.imageshack.us/img189/9131/22465062cfdd4934b51d7f5.png Hopefully the image isn't too difficult to decipher... Basically a beam balanced on to pin jointed pivots with 6 metres in between each one. Homework Equations ƩFy = 0 ƩFx = 0 ƩMP = 0 The...

Hi there everyone. I'll try to keep this short. I'm currently a sophomore at a local college. I'm in Honors Calculus 1 and part of the honors course requires a research project at the end of the semester. I'm studying to be an ER Doctor/Particle Physicist, yes I know this will take some...

I understand the idea that an unsaturated parcel of air will rise along the dry adiabat until the condensation level is reached, at which point the air is saturated with moisture. If it rises further, it will do so along the moist adiabat - but doesn't that mean at the same time that water...

Feynman Diagrams! Please Help! Hi guys! I've been asked to draw a scattering and annihilation Feynman diagram for the following scenario: e+e- → VeVe (The second Ve is an anti-neutrino just couldn't figure how to put the bar on! :P I've tried it and I'm convinced the mediating...

Do anyone have any software by which i can make a vector diagram from a group of points.you can think it like..suppose you have x & y component of a vector at a point..you can draw that easily but i will have to draw a vector diagram for 100 or more points arranged on a surface...i will give the...

Hi, Can anyone point me to a reference where the complete amplitude for a sunrise diagram in 2D with generally different masses is written down. That is, I want the value of the following integral $$ \int d^2k d^2l \frac{1}{(k^2-m_1^2)(l^2-m_2^2)((p-k-l)^2-m_3^2)} $$ where p is the...

Hi all. I am new here and I am having difficulty figuring out what exactly is required of me in this question. If someone could be so kind as to explain. For this part of the project we will consider the evolution of a discrete dynamical system given by a logistic map. We will consider a...

First, I hope this is posted in the correct section, and I'm sorry if it isn't. I am looking to create diagrams of optical setups for a technical paper. My mentor recommended using Microsoft PowerPoint, but my diagrams don't compare to those in published papers. Is there a better program...

Hi all, I'm having a small question about current flow direction indication in circuit diagrams. Its shown as current flow from +ve pole to -ve pole, but -ve pole has higher electron concentration (potential) & electrons flow from -ve to +ve. Whats the logic of showing the direction of...

Homework Statement Draw three free-body diagrams showing the forces acting on a toy suspended by a vertical spring. The diagrams should show the situations when the toy is at its equilibrium position, and above and below the equilibrium position. Homework Equations The Attempt at a...

I didn't know where to put this, because it isn't a homework or coursework I have to do but just a thing I'm trying to understand. Anyway, I have attached the problem as an image. We have a scalar quartic lagrangian in d dimensions. It says that the number of vacuum Feynman diagrams, at a...

Hello! I'm doing a modal analysis and I'm trying to extract modal parameters from my aqcuired data. I'm using the Pulse Reflex Software. I got to the point where the Software provides me with a MIF and a stability diagram and I am to choose the parameters. However, I am unsure how...

Hi, I'm studying for a course in semiconductor devices, involving pn-diodes, schottky-diodes and mosfet transistors. Just wondering if there's any good online resource that demonstrates specifically how to draw energy band diagrams for the various devices in various situations (applied...

Hello Could anyone recommend me a software to draw draw free body diagrams, vector diagrams, spherical/cylindrical coordinates systems etc. I am doing a project on electromagnetics and I am supposed to put everything in a digital format. Thanks

I'm pretty shaky with my understanding of much beyond simple tree-level calculations. When people talk about triangle diagrams, they sometimes say one will get a 'supression factor' of xxx. For example, in the consider the triangle diagram for H\rightarrow\gamma\gamma with Ws running around...

Homework Statement Homework Equations The Attempt at a Solution I always thought you put the electrolyte of one half cell on one side and the other electrolyte on the other side The answer given is C. But this includes VO2+ which is not in the initial eqn on the RHS?

Hi guys, I have a dyanamics question to ask. Thanks for the help! In the scenario there is two objects-one the box and the hand pushing it When i push an object, there will be a force acting on the object and hence a reaction force acting on my hand. So, if i were to apply 10N of force on...

Homework Statement Ok I have attached the pdf file and I have a problem with velocity phase spaces (Question 3a). Honestly, the lecture notes were not very helpful and looking online and in textbooks, they talked about solving Lagrange's equations but nothing to deal with the problem of Q3...

Ok, so I've been wrestling with the concept of ground for the past two weeks. I'm in an electrical engineering program at college, and let me preface this by saying I have no difficulty dealing with ground in a practical sense and understand its general function very well. That being said, I've...

Homework Statement You have a 10kg object that is thrown down a building. The distance from the ground to the building is 50m. The initial velocity of the object is 5 m/s. What is the applied force and what force does the object hit the ground with? Homework Equations Fapp= Fnet+Fg...

Hi. I'm looking for a drawing tool which may help me draw simple figures with vectors and angles. I've tried many but they're so complicated... e.g. Photoshop, Power Point, Edraw, and some others. The ideal one would be one which is designed for this... I mean a program that has a tool, for...

Dear PF, I am trying to draw some diagrams in jaxo draw, but I don't know how to assign Greek index whenever necessary, can you please advise me step by step... as i understand it is related to some "postscript" issues that i don't know how to set up ... would you be so kind and drop me a...

Homework Statement Hey guys I'm having trouble drawing the bending moment diagram for this beam with a hinge? I'm not sure where to start? I've looked at stuff online and its completely different to the stuff in my textbook Homework Equations equilibrium equations ƩFx=0 ƩFy=0 ƩM=0...

I think I have a pretty good handle on how scalar field scattering works in QFT, so now I'm trying to wrap my head around spin 1/2 particles, and I'm having a bit of trouble with it. For instance, in N + \phi \rightarrow N + \phi scattering, an application of the Feynman rules leads to an...

Homework Statement - Compute the reactions at the supports - Draw complete shearing force and bending moment diagrams - Determine magnitude and location of maximum absolute value of shearing force and bending moment - Use free body diagram approach to determine internal shearing force and...

Can anyone recomment any good linux software for produce "physics type" diagrams that would be of acceptable quality for putting into reports? When I say "physics type", I mean we're basically talking about straight and curved lines, vectors (arrows), angles and so on... of course I want to be...

I'm looking for some software I can use to draw reasonable technical diagrams- the sort of diagrams you'd find in online lecture notes, or in maths/engineering textbooks, i.e. simple shapes, arrows, curves etc. It's hard to describe what I mean, hence why I've came after nothing on Google...

Sorry if this appears a basic question, but could you pls advise me is it possible to have a two identical vertexes but with different strength coupling? I have some toy Lagrangian and when I calculate Feynman rules I get for one vertex following expression: (M1+M2)*(combination of...

Hi, I have a colour-colour (that is, V-R against B-V) diagram of a young open cluster, and I was wondering if anyone has any suggestions on any information that can be gleaned from such a diagram? I have searched the internet and these forums to no real avail. There is a clear linear line...

Hello my friends! I'm trying to learn the meaning of young diagrams from Christoph Lüdelins physics751 (google it :) but I can't figure out what is happening in eqn 4.14. I understand why 4.13 are the possible p-cycles but how does eqn 4.14 apply to this S_5 example? (Sorry that I could not...

Can a vertex of a Feynman diagram have more than three particles going in or out from it? Assuming all other conservation laws are obeyed, of course. I haven't seen this being explicitly stated but all the Feynman vertices I have seen have three arms attached. Thank you.

Homework Statement A circular-motion addict of mass 82.0 kg rides a Ferris wheel around in a vertical circle of radius 14.0 m at a constant speed of 7.10 m/s. (a) What is the period of the motion? What is the magnitude of the normal force on the addict from the seat when both go through (b)...

I did not find wikipedia article to be quiet intuitive. Any online sources or your own descriptions. I would be greatful.

Are the Feynman diagrams still applicable to more than two particles interactions? This would be very helpful in modelling many-body scattering cross-sections.

I am looking for a book that explains how a Schottky barrier is formed at a semiconductor metal interface. I have found the attached diagram in a source that i cannot see the references for. Does anyone know of a book containing such a diagram and an explanation of the formation of a Schottky...