Approach Definition and 545 Threads

Although we have nerves throughout the body, a person's essential personality and memories are thought to be stored more or less completely in the brain. In theory, you could transplant a brain into a new body, and the individual who would awaken would be the one whose brain is used. It would...

I stumbled on it while searching for electrodynamics textbooks for undergrads but this seems more advanced than Griffiths. Has anyone else used this book by Marcus Zahn? Is it a worthwhile read for an electrical engineer about to start sophomore year?

Homework Statement A proton and an α -particle are projected with velocity v=√\frac{e^{2}}{4∏εmL} each from infinity as shown.The perpendicular distance between their initial velocities is L .Let the distance of their closest approach be D . Given .Find (8D/L - 5)^2 Details and assumptions...

Hello! For those who took (or have been taking) the organic chemistry, which methodology do you prefer to tackle the mechanism and prediction questions? I have been reading Loudon & Wade (functional group-based) and Clayden (mechanism-based), but I feel like the mechanism-based approach is...

Homework Statement Two point charges q1=1\muC and q2=-1\muC with mass 1g each are at distance 1m from each other. The charges are released from rest at . Find the time t in seconds at which they collide. Homework Equations F=kQ1*Q2/r^2.The Attempt at a Solution Let the dist. of separation...

I'll try to develop some notation and explanations that might make the Friedman equations more intuitive to some beginners. They might look a bit odd in their new get-up--if that bothers you please simply ignore this thread. The scale-factor function a(t) keeps track of the size of a generic...

Homework Statement I'm following a procedure in a particular paper as part of my Masters project. The paper is called 'Theoretical investigation of the sound attenuation of membrane-type acoustic metamaterials - Y Zhang, J Wen, Y Xiao, X Wen and J Wang (2012)' and can be seen...

I was stuck for an hour trying to do this calculus 1 problem. Think I figured it out but it's a even problm. Find the absolute maximum and absolute minimum values of f on the given interval. f(t)=t+cot (t/2), [pie/4,7pie/4] f'=1-(1/2) csc^2 (t/2) So 1=1/2*csc^2 (t/2) 2=csc^2...

Hi, I am a 20 year old looking to work on my prerequisites for something like computer science. The problems are that: 1) Commuting is going to be difficult, I don't currently have a car. Otherwise busing is 40 minutes. 2) Work may conflict, but I can quit if necessary. Are there...

Homework Statement I am currently working as an intern in a research institute (I'm a 3rd yr undergrad) and my supervisor has asked me to create a simulation from a particular model - please see linked <http://journals.aps.org/prb/abstract/10.1103/PhysRevB.69.045202> or attached paper. I...

In certain forms - including the logarithmic - a number of the trigonometric and hyperbolic functions can be used to sum series having Riemann Zeta and Dirichlet Beta functions (in the general series term). In this tutorial, we explore some of these connections, and present a variety of Zeta and...

Homework Statement An alpha particle is accelerated from rest through a potential dierence of 20 kV. It travels directly towards a stationary Beryllium nucleus (4 protons, 5 neutrons). Calculate the distance of closest approach. The problem definitely wants a solution that takes into account...

Was this technique ever demonstrated experimentally, or it could be regarded as practically failed theory? https://lasers.llnl.gov/science/ignition/fast-ignition

Homework Statement Solve the system x'' + αx = 0 x = [ x1 x2 ] α constant Homework Equations x'' + αx = 0 Where x is a vector [x1 x2] The Attempt at a Solution The solution of x'' + αx = 0 is x = Acosh(√α x) + Bsinh(√α x) Differentiating x x' = √α*Acosh(√α x) +...

Hello physics forum, I am a physics major who is currently working on getting my bachelor's degree , and also considering on majoring in mathematics. I find physics and mathematics very interesting and exciting . I want to asks , how can I improve as physics and mathematical student ?

Hi All, In the Feynman, 'sum over paths' approach to quantum field theory, we compute amplitudes, generating functionals etc by feeding in a "classical action". By calling the Lagrangian that we feed in "classical", this mean that the fields that feature in that action are regarded as...

Homework Statement By considering different paths, show that the given function has no limit as (x,y) \rightarrow (0,0). f(x,y) = x4/(x4 + y4) Homework Equations The Attempt at a Solution My instructor taught me this process a while back and am unsure if it fits for this...

Hello, I have seen (in H Cartan's differential calculus) a proof that if F is a Banch space, L(E,F) where E is some vector space, is also a Banach space. One of the main points of the proof is based on the behaviour of a function being "proper" (continuous) on a ball of arbitrary radius "n"...

Find the mean square error using the pseudo inverse approach. I am given a 11X9 matrix A, a 11X1 vector F and R = 11X11 diagonal matrix so Rhat = A[(A'A)^-1 ]A' R . Then I get a 11X11 matrix. Shouldn't I get getting a 8X11 matrix How do I get the most optimum vector F?

A motorist drives south at 32.0 m/s for 4.00 min, then turns west and travels at 55.0 m/s for 5.10 min, and finally travels northwest at 12.0 m/s for 2.00 min. Find the following values. 1.total vector displacement (m) at a _ degree south of west 2.average speed (m/s) 3. average velocity m/s...

If you are going on a long trip is there a difference between going half the distance at 45mi/h and the other half at 50mi/hour, compared to going half the time at 45mi/h and the other half at 50mi/h?So wouldn't the first part be: (95)/60? The second part would be: (95)/30 Or would it be...

Hi guys, I need to simulate wave propagation for a nonlinear dispersive wave PDE and since I can't find proper resources for handling nonlinear PDEs numerically, I would appreciate any help and clues. the PDE is in the form of utt-(au+bu2+cu3+duxx)xx=0 Romik Ps: BC: Clamped at both ends IC...

In... http://mathhelpboards.com/questions-other-sites-52/unsolved-analysis-number-theory-other-sites-7479-3.html#post38136 ... it has been found the value the integral... $\displaystyle \int_{0}^{2\ \pi} \sqrt{1 + \sin^{2} x}\ dx\ (1)$ At first it seems feasible to set $z = e^{i\ x}$ and the...

A while ago, pinkybear posted the following: Homework Statement A fire hose for use in urban areas must be able to shoot a stream of water to a maximum height of 35 m. The water leaves the hose at ground level in a circular stream 3.5 cm in diameter. What minimum power is required to create...

Homework Statement Draw graphs of weight against time for the following 1) man stands on scale very gently and then gets off again very gently 2) man jumps onto scales and then jumps off again 3) man stands on scale and let's his knees unlock so that he drops, then stops. For each of...

"Hearing a drum's shape" as approach to quantum gravity (Kempf) Achim Kempf and his students have coded an ITERATIVE procedure for finding the shape that when struck has a given sound spectrum. He shows brief movie clips of the computer finding the correct shape by successive approximations, as...

I can't think of an elegant way to do it, and yet I need to, somehow. If you have a period followed by a space, then you know you're at the end of a sentence. Same with a period followed by a quotation marks (in the American way of writing. In the British way, they keep the quotation marks...

Hey all, I am interested in pursuing an M.Eng upon completion of my undergraduate. At my university, this entails 30 credit units and a project. Hence, the main priority is for one to find a professor who is willing supervise them during the project. I am completely ignorant when it comes to...

hi guys, i am going to machine aluminum using EDM die sinking to study the MRR, TWR and Surface finish. i have read many papers where "One Variable at a Time Approach is used" but do not understand how the input parameters are chosen or i can choose them randomly? thanks

Given in my book- 1."Velocity Of approach - It is the rate at which distance between two moving particle decreases. V(Approach) =V1cosα + V2cosβ " 2."When the distance between two particles is minimum, the relative veloctiy of approcah is 0" 3."V1cosα + V2cosβ = 0 ...when distance is...

Homework Statement The problem describes an aircraft taking off from a point on a runway with constant speed V_{1}, climbing at a constant angle \alpha, at the point of takeoff, a car drives towards the aircraft a distance a away with speed V_{2}. I simply have to find the closest distance...

Usually in the problems I have done, I found the partition function by simply summing exponential of the eigenenergies, but lately I have started to wonder why this approach is correct. Do we not want to sum over the energies of all possible states as we did in the classical case. In that case...

Ecologists use the following model to represent the growth rate process of two competing species, x and y: dx/dt=r1x(1-x/K1)-α1xy dy/dt=r2y(1-y/K2)-α2xy Let x= number of blue whales (measured in 100,000's) y=number of fin whales (measured in 100,00's) t=time measured in centuries...

Non-locality is based on the assumption that the act of observing causes an effect instantaniously elsewhere. It occurred to me that we can't be certain that one thing(observing) is causing the other(non-local wave function collapse). Another solution might be that both events are...

Homework Statement I'd like to figure out the moment at pt A using the scalar approach, not vector Homework Equations Vector M = r x f Scalar M = fd The Attempt at a Solution I think I might be missing some concept that would make my life easier... I figured out how to...

Homework Statement A particle with mass=m moves in the xy plane. It is under the influence of a repulsive central force described by: F(r)={A\hat{r} if r<R0 and 0 if r>R0} \hat{r} is the unit radial vector and R0 is the range of the force The initial conditions are x=-3 R0, y=0.5 R0...

We know that a shell can accommodate a maximum of 2n2 electrons because a shell can have a maximum of n2 orbitals depending upon the value of n, i.e n=1 for K shell, n=2 for L shell, n=3 for M shell, n=4 for N shell and so on. According to Lewis, he pictured the atom in terms of a positively...

How I currently approach a difficult problem: -draw a diagram -list out all the given variables and "solve-for" variable --use variables to match to a formula [SIZE="1"]("oh they didn't give the time, I should use the formula V^2-V0^2 = 2*a*(S-S0)," or "I have a, t, and V0, and assuming S0 is...

Does anyone have an intuitive explanation for why torque depends on the perpendicular distance from the axis of rotation? I understand the maths and fully accept the truth of the description, but CANNOT wrap my brain around the reason. The ball and spring model of a solid seems like a place to...

Homework Statement Uniform plane of charge. Charge is distributed uniformly over a large square plane of side ##\ell##, as shown in the figure from the uploaded file (see file). The charge per unit area (C/m^2) is \sigma. Determine the electric field at a point ##P## a distance ##z## above...

Hey everyone, I'm starting to learn physics on my own and I'm doing the chapter review questions at the end of the chapter. Right now, I'm on units and problem solving. My question to you guys is should I be concerned about actually knowing the exact measurement to solve the problems, or is...

Given the following axioms: For all a,b,c we have: 1) a+b = b+a 2) a+(b+c)=(a+b)+c 3) ab = ba 4) a(bc) = (ab)c 5) a(b+c) =ab+ac NOTE,here the multiplication sign (.) between the variables have been ommited 6) There ia a number called 0 such that for all a, a+0 =a 7)For each a, there is a...

Given the following axioms: For all a,b,c we have: 1) a+b = b+a 2) a+(b+c)=(a+b)+c 3) ab = ba 4) a(bc) = (ab)c 5) a(b+c) =ab+ac NOTE,here the multiplication sign (.) between the variables have been ommited 6) There ia a number called 0 such that for all a, a+0 =a 7)For each a, there is a...

Hi all, I am new to the forum :) and was hoping that you guys could help me out with the problem i am facing when solving the logistic population model: taking different steps during the integration process seems to produce different results. I am very sorry for the long post :(...

Given the following axioms: For all a,b,c we have: 1) a+b = b+c 2) a+(b+c)=(a+b)+c 3) ab = ba 4) a(bc) = (ab)c 5) a(b+c) =ab+ac NOTE,here the multiplication sign (.) between the variables have been ommited 6) There ia a number called 0 such that for all a, a+0 =a 7)For each a, there is a...

There's this cute girl I constantly see at my university library. I would like to meet her but I'm scared of interrupting her. She seems so focused on her stuff and the library is really quiet so I feel weird approaching her. I tried to peak at what she was working on and all I could see were a...

It may just be because I probably got only an hour of sleep last night and my thinking skills are not very good, but I'm grading a question on a final exam in discrete math and a lot of stiudents gave an answer that is incorrect, but I can't see why it is incorrect. Homework Statement Given...

I'm currently reading "Three roads to Quantum Gravity" by Lee Smolin. In the book he describes attending a presentation by Fay Dowker and James Hartle about the consistent histories approach to quantum cosmology. He describes that, "there were worlds that were classical now that were arbitrarily...

Hi:Me and my team are currently building a 3d printer for a senior project, and throughout this project I have noticed that we often run into problems with calibration, drivers, etc. we find this troublesome because we often find it hard to identify the source of the problem.So my question is ...

1. Problem is in the Attachment This link will help your figure these question...