Elementary Definition and 537 Threads

simple magnetic dipole moment with impossible field lines? clueless. Hello, I'm taking a first year university course in electromagnetism. At a certain point we came upon the torque on a current loop in a uniform magnetic field. There we introduced the magnetic dipole moment \overline{\mu} =...

Homework Statement Estimate the number of low and high mass stars that you expect to find in our Milky Way Galaxy now. Use the following (very approximate but about right numbers) for your estimate: The Star Formation Rate in our galaxy is approximately 1 Solar Mass per year and virtually...

I am looking forward to study Particle physics on my own. Can someone suggest me a book which I can read and understand by myself?

Two basic questions here, thanks and good karma to whoever helps. my questions are: The spin of an elementary particle, is it really the physical rotation of a particle on its axis? and Can I imagine that an elementary particle looks like a three dimensional wave packet laying/distorting the...

I am looking for an easy way to explain to my 2nd grade son which ball will roll down a ramp faster. I have a ramp (more like a trough) set at about 30 deg angle incline. He is going to roll a baseball, pool ball, golf ball, and basket ball down the rramp. He is only 2nd grade so I can't get...

I am aiming to prove that p is the smallest prime that divides (p-1)!+1. I got the first part of the proof. It pretty much follows from Fermat's Little Theorem/ Wilson's Theorem, but I am stuck on how to prove that p is the smallest prime that divides (p-1)! +1. I am assuming that every...

This result came up in my diff eq class the other day: If i = x^2 then x = [(sqrt(2)/2) + (sqrt(2)/2)i]^2 While there aren't a lot of use for complex numbers in this class, I still feel stupid for not knowing it. Another trick that I'd like to learn about is the "complexifying the...

I have a question about elementary matrices, I have matrix A, and I just found A-1, and then the question wants me to write A-1 as a product of elementary matrices. Ok, that's easy, but now the question wants me to write A as a product of elementary matrices, how do I go about doing this...

The first part of the problem is as follows: Any nonempty set of integers J that fulfills the following two conditions is called an integral ideal: i) if n and m are in J, then n+m and n-m are in J; and ii) if n is in J and r is an integer, then rn is in J. Let Jm be the set of all integers...

Homework Statement What is the inverse of this elementary matrix? 2x2 matrix 1 0 3 -1 E= Homework Equations None The Attempt at a Solution This is what I think: 1 0 -3 -1 Is that right? Or do you leave the 3 positive? If so, please explain. Thank you.

Homework Statement A= 1 2 -3 B= -1 2 0 0 1 2 0 1 2 -1 2 0 1 2 -3 Find an elementary matrix E such that EA=B Homework Equations None The Attempt at a Solution I don't know how to start this problem. Please help. Thank you.

It is said on wiki* that "Maximal compact subgroups are not unique unless the group G is a semidirect product of a compact group and a contractible group, but they are unique up to conjugation, meaning that given two maximal compact subgroups K and L, there is an element g in G such that...

Homework Statement Given A = \left( \begin{array}{cc} 2 & 1 \\ 6 & 4 \end{array} \right) a) Express A as a product of elementary matrices. b) Express the inverse of A as a product of elementary matrices. Homework Equations The Attempt at a Solution Using the following EROs Row2 --> Row2 -...

Hello, Given a function f(x_1,\ldots,x_n), the total derivative for x_1 is: \frac{df}{dx_1}=\frac{\partial f}{\partial x_1}+\frac{\partial f}{\partial x_2}\frac{dx_2}{dx_1}+\ldots+\frac{\partial f}{\partial x_n}\frac{dx_n}{dx_1} Now, if the x_i are just variables, can we say that...

If there's no tail rotor, Will the body of helicopter naturally turn along with the main rotor (in the same direction) or spin toward the opposite direction. Thanks! $15 bet with my friend ><

***SOLVED*** Homework Statement A system of particles is at equilibrium. What is the proportion of particles in the ground state? The Attempt at a Solution P(\epsilon_{s})=\frac{exp(-0/\tau)}{1+exp(\frac{-\epsilon_{s}}{\tau})+exp(\frac{-2\epsilon_{s}}{\tau})} Is that right? This is a...

Homework Statement An elementary particle called the omega minus has spin 3/2. Calculate the magnitude of the spin angular momentum for this particle and the possible angles the spin angular momentum vector makes with the z-axis. Does this particle obey Pauli’s exclusion principle...

Is it just me or does just knowing a few physics formulae make first year physics courses ridiculously easy? I have a few sample tests in front of me and just about every single question can be answered by applying 1 of about 10 formulae in one way or another. I always liked physics but only...

Has anyone ever considered the outer event horizon of a point particle (classical electron perhaps...)? Does it make sense to consider it Kerr and charged because of spin? Is it comparable with a Planck length? I know we would need a quantum gravity to deal with it, I'm just curious to see what...

Can anyone provide an elementary argument for why the zero mass of the photon means that it can't be longitudinally polarized? I know of at least one non-elementary argument, which is that if you write down the Proca equation, it only has longitudinally polarized solutions if the mass is...

A lot of apparently innocent elementary functions, like exp(-x^2) or (sin x)/x, have not antiderivatives in terms of elementary functions. I've read that "Differential Galois theory" explains this, and gives an algorithmic method to know if a given elementary function has or has not elementary...

Free elementary particles are lighter than the Planck mass, how can the exist as particles, or are they just Compton particles having a Comton waveleght?

I hope that someone here can answer this question... I have an 18 lb. turkey that needs to be thawed in cold water over 9 hrs., with the cold water replaced every 30 minutes. If I use a container about 3 times the size of the sink, will that allow me to change out the water every hour and...

NOTE: This is not a homework question. Rather, this is a conceptual question I developed as I was reading the book. 1) Aren't we a little heavier than what the scale says (a very miniscule amount) because the buoyant force is equal to p sub fluid times g time volume that is submerged? 2)...

Hello, I need to find some theory about elementary matrices. That are the matrices in the form \mathbf{E}(\sigma,\mathbf{u},\mathbf{v})=\mathbf{I}-\frac{1}{\sigma}\mathbf{uv}^{T} I can't find anywhere some theory about it. Can you give me some useful links? Thank you so much...

After suggestion to search for black holes at LHC one can ask how much black hole is similar to the elementary particle? Can we apply second quantization to the field of black holes? Can we talk, for instance, about cosmological black holes production in analogy with cosmological...

Homework Statement First of all, a bit about myself. I have just graduated from high school in Canada and now going to University for First-Year Engineering. I am having quite a bit of difficulty grasping even some of the so-called elementary concepts like basic quantum mechanics etc. Part of...

Homework Statement Show that any multiple of a row can be added to a row above it by row operations of other types. Homework Equations There are only 3 elementary row operations. i. Interchange two rows ii. Multiply a row by a constant iii. Add a multiple of a row to another row. The...

I was doing my differential equations homework. I had to solve y'' -4y = (e^(2x))/x. While doing this I ran into an integral\int\frac{e^{4x}}{4x}dx. I tried integrating my times but I couldn't; my guess is that this cannot be integrated in terms of elementary functions but I'm not sure. Is...

Im really good at number theory but how to show this statement has me stumped! "Show that among the positive integers greater than or equal to 8, between any two cubes there are at least 2 squares"

Can we see elementary particles using any device? I mean the way we can observe smallest of the viruses by a microscope and the farthest of the objects by a telescope?

I've seen this many times: someone will post a homework question asking them to prove something about an integral \int_a^b f(t) dt , where f is some arbitrary, continuous, integrable function. They will write in their proof, \int_a^b f(t) dt = F(b) - F(a) where they're assuming F is the...

I have a question regarding the attached file. How do you get those indicies when you multiply the kronecker deltas with A, B, and C? For instance, C - subscript m remains the same on the left side of the expression, but then becomes C subscript i on the right side. How does this logically...

Homework Statement Sorry for the double post, I couldn't re-edit the topic on my earlier post. The assignment is to represent the following matrix as a product of elementary matrices: 1 3 5 3 10 11 -2 -7 -7 I reduced this matrix down to the identity matrix I using elementary row operations...

Homework Statement Determine if the set of points (x,y) on y = |x-2| + 3 - x are bounded/unbounded, closed/open, connected/disconnect and what it's boundary consist of. Homework Equations The Attempt at a Solution I know that the set is closed, and then by definition of a closed set...

Introduction to Analysis by Maxwell Rosenlicht https://www.amazon.com/gp/product/0486650383/?tag=pfamazon01-20 Elementary Real and Complex Analysis by Georgi Shilov https://www.amazon.com/dp/0486689220/?tag=pfamazon01-20 Introductory Real Analysis by Kolmogorov...

Recently I have begun thinking about the function x^x. I am well aware that there is no elementary function to define it's antiderivative, and intuitively it makes sense (I cannot think of an elementary function who's derivative is x^x). However, how would one go about proving this rigorously?

Another question that i am not even qualified to ask: So i know that all the quarks have a job creating mesons and baryons. And i know the electron is a lepton with a very important job with the structure of an atom. But what is the importance of the muon, the tao, and all three nutrinoes...

Does anyone know any good book(s) about elementary particles?

Shankar p68-69 gives a mathematical "derivation" of the action of the X (position) operator, the summary of which is as follows: I followed the logic without a problem, since it only involves using the matrix elements of X in the basis of eigenfunctions of X. However, the next paragraph reads...

"Elementary excitations" VS. "Quasiparticles" What's the difference between "Elementary exitations" and "Quasiparticle"? Thanks!

Has TEW been discussed here? My apologies if so. I'm not sure where to start the discussion of this topic, so I thought I'd start at this forum, which should show you the way I'm leaning. Still, Dr. Little seems quite learned and TEW has me thinking in interesting directions. I won't link to a...

Following is a summary from Chapter 20 of Leonard Susskind's 2008 book THE BLACK HOLE WAR: I'd appreciate any further insights, especially on interpreting what Susskind says about String theory as it was vague for me. These are not exact quotes. Elementary particles are usually imagined to be...

Hi all, I'm trying to teach myself the basics of QFT. I'm using Peskin and Schroeder, and having a few difficulties reproducing a couple of the calculations. I don't think I've made careless algebraic slips, so before I show my working explicitly and beg for proof-reading I'd like to ask a...

What does "collision" mean when dealing with elementary particles? Can someone point me to some online references that will get me started in understanding what is meant by a particle collision? The issues I don't understand- Leptons and quarks are supposed to be point particles. Do they...

Homework Statement Suppose that a teacher wishes to distribute 25 identical pencils to Ahmed, Bar- bara, Carlos, and Dieter such that Ahmed and Dieter receive at least one pencil each, Carlos receives no more than five pencils, and Barbara receives at least four pencils. In how many ways can...

Homework Statement Here's the problem I don't understand and its solution: http://img11.imageshack.us/img11/5867/24545624.gif Homework Equations The Attempt at a Solution I want to write the original matrix as a product of elementary matrices but I don't know they got that...

Are there elementary, massive particles with zero spin? Thanks in advance.

Homework Statement A farsighted woman breaks her current eyeglasses and is using an old pair whose refractive power is 1.655 diopters. Since these eyeglasses do not completely correct her vision, she must hold a newspaper 39.4 cm from her eyes in order to read it. She wears the eyeglasses...

Hi, could anyone please tell me equations 6.34 and 6.31 from Griffiths elementary particles book ( the new edition)? I need to do problem 6.5, I have the old book, and I can't make any connection. Can't find the new book either right now, and I need to do it by tomorrow.. Please help, i'd...