Griffiths Definition and 230 Threads

Ok, maybe the subject has been discussed in some manner in other posts, but I would like a clear comparison between : * David J Griffiths - Introduction to Quantum Mechanics * Shankar - Principles of Quantum Mechanics * Sakurai - Modern Quantum Mechanics What is your experience with these...

This may sound a bit neurotic, but after trying the calligra and frcursive packages, I feel I'm still missing out on a good, general-purpose script font for math. I'm looking for something like the script "r" on page 9 of Introduction to Electrodynamics and the script "S" and "s" on page 121 of...

Hi all. I'm reading about time-independent perturbation theory for degenerate states in Griffiths' Introduction to QM. I have a question on the things he writes in chapter 6.2, page 269. What does he mean by the so-called "good" linear combinations? I hope you can shed some light on...

In Griffiths' text "Introduction to electrodynamics", p.125, how does the author get (3.15) and (3.16)? I try for an hour to deduce the relation with geometry, but still can't get that.

Okay, here's a quantum mechanics problem. I am just starting with quantum, so I have no idea about this stuff. I am requesting guidence or a push in the right direction, not nessicarily a complete answer, please. Also, I don't know if this fits into the Advanced Physics help forum. I've never...

When finding the polarization of the dielectric portion between the two plates using P=\epsilon_{0} X_{e}E, why would we use the E-field in the air portion (as is done in the solutions manual and here: http://www.getofftheinternet.net/s_10077.pdf ) instead of solving for the E-field in the...

I'm having a hard time understanding example 5.8 in Introduction to Electrodynamics by Griffiths. Why, exactly, is Ienc = KL? It makes sense intuitively, but I don't see how to get this result explicitly -- shouldn't the line integral be along the y-axis, and since \bar{K}=K\hat{x}, shouldn't...

Homework Statement This is from Prob. 2.25 Two point charges with separation d, P is a point at a distance z above the mid-point of the charges. The last sentence asked if one of the positive charges is changed to a negative one, what is the potential at P? What field does it suggest? Explain...

Hello everyone. I wanted to make this thread to asks lecturers to please stop using Grffith's book "Introduction to Quantum Mechanics" as the required text for undergraduate physics, and to warn students about it. Please read this, as I truly believe Griffiths' book is a rip-off, nevermind a...

Homework Statement Griffiths Particle Physics, problem 7.24. Evaluate the amplitude for electron-muon scattering in the center-of-momentum system, assuming the e and mu approach one another along the z-axis, repel, and return back along the z-axis. Assume initial and final particles to...

Howdy everybody. I've browsed this forum many a time but this is my first time posting. Anyways. I'm taking QM in the fall for the second time (the sole reason i didn't graduate this semester), and so I'm going through the griffiths book right now so i can ace this class next time around. I'm...

[SOLVED] griffiths 6.5 Homework Statement A uniform current density \mathbf{J} = J_0 \hat{\mathbf{z}} fills a slab straddling the yz plane x=-a to x=+a. Find the magnetic field inside the slab. This is part of Griffiths Problem 6.5. Homework Equations \nabla \times \mathbf{B} = \mu_0...

[SOLVED] Griffiths 7.3 Homework Statement Two metal objects are embedded in weakly conducting meterial of conductivity of \sigma Show that the resistance between them is related to the capacitance of the arrangement by R=\frac{\epsilon_0}{\sigma C}Homework Equations The Attempt at a Solution...

I have the first edition of Griffiths's "Introduction to Quantum Mechanics" and am considering using it (or rather the second edition) for a junior/senior level undergraduate course next spring. What makes the second edition different? I should just get a copy, I know, but I'll probably have to...

Hi there Griffiths uses a nice notation for the vector from the source point to the field point --a "squiggly r" -- in his E-M textbook. He calls it a "script letter". It makes many ugly expressions look much simpler. Anyway, nice as it is, does anyone who has used Griffiths know how to...

[SOLVED] Griffiths dipole moment Homework Statement On page 244 of Griffiths E and M book, Griffiths defines the magnetic dipole moment as \vec{m} = I \int d\vec{a} . Then in problem 5.58, he asks us to calculate the dipole moment of a uniformly charged spinning solid sphere. How is that...

[SOLVED] Griffiths Problem 5.41 Homework Statement This question refers to Griffiths E and M book. http://www.phys.unsw.edu.au/~gary/PHYS2050_Tut_5.pdf Homework Equations The Attempt at a Solution Am I supposed to assume that the initial velocity is perpendicular to the B-field i.e. in the...

Homework Statement This question refers to Griffiths E and M book. Am I supposed to use special relativity to do this problem? It seems out of place in Chapter 5 if I do? http://www2.andrews.edu/~mattingl/courses/phys431/incomplete_probs_griffiths3ed_w99.PDF Homework Equations The Attempt at...

Homework Statement This question refers to Griffiths E and M book. An uncharged conducting sphere of radius a is coated with a thick insulating shell (dielectric constant \epsilon_r) out to radius b. This object is now placed in an otherwise uniform electric field \bfE_0. Find the electric...

[SOLVED] Griffiths Problem 4.16 Homework Statement This question refers to Griffiths E and M book. Is Figure 4.18 a mistake? It says the polarization is uniform, not radial! Homework Equations The Attempt at a Solution

[SOLVED] Griffiths Problem 4.8 Homework Statement This question refers to Griffiths E and M book. Why is the answer not 2 times that? Why don't you need to add the energy of dipole 1 to the energy of dipole 2 like \bf -p_1 \cdot E_2 - p_2 \cdot E_1 ?Homework Equations The Attempt at a...

[SOLVED] Griffiths Example 5.8 Homework Statement This question refers to Griffiths E and M book. In this Example, Griffiths says "the z-component of the B-field cannot possibly depend on the direction of the current in the xy plane. (Think about it!)" I thought about it and thought about...

Homework Statement This question refers to Griffiths E and M book. Of course I am stuck with the integral. I chose z to be in the same direction as the polarization. The integral is then P \int d\Omega r'^2 dr'\frac{\left(\mathbf{r} -\mathbf{r'}\right)\cdot...

Homework Statement This question refers to Griffiths E and M book. See the solution here http://www.physics.gatech.edu/academics/Classes/fall2005/3122/hw9solution.pdf I don't understand why they say the torque we exert is clockwise (I assume that means in the minus z direction). Homework...

Homework Statement This question refers to Griffiths E and M book. The first equality makes perfect sense to me. It is a standard path-integral along the wire FOR EACH COMPONENT OF THE INTEGRAND. It is defined just like this (for each component) \int_C f\, ds = \int_a^b f(\mathbf{r}(t))...

Homework Statement This question refers to Griffiths E and M book. To finish the problem, I just need to show that \frac{d}{dt}\int_V \vec{r} \rho d\tau = \int_V \vec{r} \frac{\partial \rho}{\partial t} d\tau When you apply the product rule to the integral, why do you get \frac{\partial...

Homework Statement This question refers to Griffiths E and M book. I am confused about what the answer should be in terms of. Usually he gives us all constants that might be needed in the answer. But we need to know that distance between the plates here don't we? Homework Equations...

[SOLVED] Griffiths page 182 Homework Statement This question refers to Griffiths E and M book. This page has been confusing me immensely over the past two days. First, can someone explain the logic in the statement below Figure 4.21 "so D can be found from the free charge as though the...

[SOLVED] Griffiths Problem 4.18 Homework Statement This question refers to Griffiths E and M book. Obviously we are supposed to use equation 4.23 here. But for that to be of any use, we need to assume that the electric displacement is orthogonal to the plates. We are told that the medium is...

[SOLVED] Griffiths page 176 Homework Statement Below example 4.4, Griffiths says "We cannot apply Gauss's law precisely at the surface of a dielectric, for rho_b blows up..." Why does rho_b blow up? Homework Equations The Attempt at a Solution

[SOLVED] Griffiths 4.10 Homework Statement This question refers to Griffths E and M book.Homework Equations The Attempt at a Solution part a was easy. For part b, I am trying to calculate V(r) using equation 4.13 and I am facing an absurdly difficult integration which means I must be doing...

[SOLVED] Griffiths torque on a dipole Homework Statement This question refers to Griffiths E and M book. In the sentence after equation 4.5, Griffiths says the following: "For a perfect dipole of infinitesimal length, Eq 4.4 gives the torque about the center of the dipole..." What is...

[SOLVED] Griffiths eqn 4.5 Homework Statement This question refers to Griffiths E and M book. \vec{F} = (\vec{p} \cdot \nabla)\vec{E} Can someone please explain what the expression in parenthesis is? I have never seen that before? Is it a vector or a scalar or an operator or what? And what is...

if i read griffiths particle physics book will I have enough knowledge of the subject material to start reading peskin and schroeder's qft book or will I still have to learn graduate mechanics and electrodynamics first before starting on that. If I do need to look at graduate mechanics and...

Homework Statement I have a problem exactly like problem 4.10 in griffiths, however that problem is not being much help since it seems to me that they just plug in P(r). For those who do not have griffiths the question is: A sphere of radius R carries a polarization P(r)=kr where k is a...

[SOLVED] Griffiths induced charge Homework Statement I am so insanely confused about induced charge. Griffiths does this problem in which a charge q is held a distance d above an infinite grounded conducting plane and then he calculates that the induced charge on the plane is -q (section...

Homework Statement This question refers to Griffiths E and M book. Homework Equations The Attempt at a Solution Obviously this is a 3D problem and we should use Example 3.5 as a model. However, since the region of interest is bounded in all 3 directions doesn't that mean that all...

Homework Statement This question refers to Griffiths E and M book. If they had not told me that the charge moves, I would have guessed that it just sits there since it seems like there is nothing to exert a force on it. Am I supposed to calculate the induced charge on the conducting plate...

[SOLVED] Griffiths Problem 3.1 Homework Statement This question refers to Griffith's E and M textbook. I am stuck trying to calculate the average potential on the sphere due to the enclosed charge. It seems like he used something like Gauss's Law but I don't see how to get the average...

[SOLVED] Griffiths problem 2.37 Homework Statement Two large metal plates (each of area A) are held a distance d apart. Suppose we put a charge Q on each plate; what is the electrostatic pressure on the plates? Homework Equations The Attempt at a Solution I am so helplessly...

[SOLVED] Griffiths Problem 3.28 Homework Statement Please stop reading unless you have Griffiths E and M book. In this problem, I found that the approximation agrees with the exact potential. I am not sure what to conclude about higher multipoles. Are they all identically zero or do they...

[SOLVED] Griffiths page 150 Homework Statement Please stop reading unless you have Griffith's E and M book. On this page, Griffith's start talking about "pure" and "physical" dipoles. Can someone define what these terms mean? Homework Equations The Attempt at a Solution

[SOLVED] Griffiths page 146 Homework Statement EDIT: sorry I realized I posted this in the wrong forum; someone can move it to the advanced physics forum if you want Please stop reading unless you have Griffiths E and M book. On that page, Griffiths says "and then the binomial expansion...

at what level is griffiths particle physics book at, what does it expect you to know as a prerequisite?

[SOLVED] Griffiths Example 3.6 Homework Statement Please stop reading unless you have Griffiths E and M book. In Example 3.6, we must assume that there is no charge inside the sphere even though it does not explicitly state that? Or is that what "hollow" means? Homework Equations...

Homework Statement Please stop reading unless you have Griffiths. In part a, he says that I know the answer in advance. I actually don't. Why should I? Homework Equations The Attempt at a Solution

[SOLVED] Griffiths Example 3.8 Homework Statement Please stop reading unless you have Griffiths E and M book. In Example 3.8, Griffiths makes two claims without justification that I want justification for. First, he says that V=0 in the equatorial plane (I assume this means that x-y plane)...

Homework Statement Please stop reading unless you have Griffith's E and M book (3rd Edition). Maybe I am nitpicking, but I think the sign is wrong on the last equation on page 80. The formula for the potential was V(\vec{r}) = -\int_{O}^{\vec{r}}\vec{E}\cdot d\vec{l} Thus when you come in...

[SOLVED] Griffiths page 124 Homework Statement Stop reading if you do not have Griffith's E and M book. Can someone explain why he says "But in the second case only the upper region contains a nonzero field, ... " ? I don't understand why the field is necessarily zero in the lower...

[SOLVED] Griffiths Problem 3.4 Homework Statement Prove that the field is uniquelly determined when the charge density rho is given and either V or the normal derivative \frac{\partial{V}}{\partial{n}} is specified on each boundary surface. Do not assume the boundaries are conductors, or that...