Classical Definition and 1000 Threads

Hi I need to relearn classical mechanics. More specifically, I need to relearn everything in this PDF: http://www.springer.com/cda/content/document/cda_downloaddocument/9783319195957-t1.pdf?SGWID=0-0-45-1509999-p177402416 However, since I have taken this course before, I want to be a little...

So hi everyone, I'm a freshman in Physics and in a couple weeks I'm going to start my second semester, with Chemistry and two exams of Classical Mechanics (Theoretical and Practical). In our first semester we had Calculus, Linear Algebra and C Programming. Since our Calculus program went as far...

Hi all! I'm super lost on this homework question. I tried asking the professor but was kind of brushed to the side. My vector calculus knowledge is pretty limited (I had an unfortunately experience in that class). Anybody have any ideas on how to go about solving for this? It's a problem out of...

I got a copy through interlibrary loan. 1950 and it looks great. While the textbook I bought in 2012 for $60 has the pages all warped and turning yellow. They don't make 'em like they used to. I can buy a used hardcover copy of the first edition for $21. I might go for that. Some joker...

I have a hard time understanding what a channel that transmits classical information is in the framework of quantum information theory. My textbook says the following: Let P(ylx) be a classical channel defined by a conditional probability distribution. We define the corresponding quantum...

I think I have an interesting thing to say on the foundation of classical mechanics and I wonder what would be the best journals to submit a work on that topic.

Why do billiard balls does not pass through both the slits at once or tunnel through walls while electrons and photons do? Quantum phenomena are observed at room temperatures so how does decoherence theory account for such phenomena? I think only Caslav Brukner and Johannes Kofler have seriously...

I was told in high school that Rutherford's atomic model was wrong because an electron which is in acceleration must release energy. That's how electromagnetic waves are made. and then I was told that Bohr gave his model and solved this problem. By making energy quantized. But what I really...

Hey all. I've started to read and watch lectures on string theory. usually everyone starts with a classical relativistic particle action, and then goes to a classical relativistic string action. after they finish with the classical string they start the quantization process. my question is...

Mod note: Moved from Homework section 1. Homework Statement Understand most of the derivation of the E-L just fine, but am confused about the fact that we can somehow Taylor expand ##L## in this way: $$ L\bigg[ y+\alpha\eta(x),y'+\alpha \eta^{'}(x),x\bigg] = L \bigg[ y, y',x\bigg] +...

What parts of Classical Mechanics must someone know before studying Quantum Mechanics in order to understand the former in all its glory? Thank you

I've started reading the book on the title, but exists so fuzz here about this book and it's scared me a bit, I'm in the middle of chapter 2 right now, and nothing difficult appeared to me in this moment, what are the requeriments to read this book smothly until the end?

Homework Statement [/B] What is the effective spring constant for the system of the two springs, perfect pulley, and string shown on the left for it to be modeled by just one spring (constant keff) as shown on the right? Use only the variables k1 and k2 in your answer. The Attempt at a...

Hi, I was wondering what textbooks I should be looking at to learn classical mechanics. I have spent a lot of time looking, but none of the ones I found had what I was looking for. For example, one book would cover all basic concepts in classical mechanics, but then it wouldn't cover more...

Homework Statement A block of mass M is positioned underneath an overhang that makes an angle θ > 0 with the vertical. You apply a horizontal force of Mg on the block, as shown in the figure. Assume that the friction force between the block and the overhang is large enough to keep the block at...

Homework Statement Given the force ## \vec{ F }(x) = (-12x + 6) \vec{i} ## ; find kinetic energy ## T## at the point ##x=2## and trajectory of a particle ## \vec{r}(t) ##, given that ## \vec{r}(t=0)=\vec{0}## and ##\dot{\vec{r}}(t=0)=\vec{0}## . 3. The Attempt at a Solution Since...

Homework Statement A particle of mass m=4.0 kg is moving along the x-axis. The particle is being acted upon by a variable single force F⃗ , directed along the x-axis. At t=0 s, the particle is moving at v_0=−3 m/s. What is the first time t>0 when the particle comes to a stop momentarily...

A small block of mass m slides on a long horizontal table when it encounters a wedge of mass 2m and height h The wedge can also slide along the table. The mass slides up the wedge all the way to the top and then slides back down, never getting over the top. All surfaces are frictionless...

Dear Physics Forum advisers, I am a collegiate junior with double majors in the mathematics and computer science. I bought a classical-mechanics book written by Herbert Goldstein in order to aid my current undergraduate research, grow my curiosity in the physics, and prepare for upcoming...

Homework Statement The statement of the question is:A chain of uniform linear mass density ##\rho##, length ##b## and mass ##M## hands as shown in the figure below. At time t=0, the ends A and B are adjacent, but end B is released. Find the tension in the chain at point A after end B has...

The classical problem of radiation reaction classical electrodynamics seems to be a huge mess with no good answer. There is no even consensus of the very form of the Newton law "predicted" theory. So, the question of this thread is: Does the classical limit of QED say something about this...

In Matrix, Morpheus shows how to jump. He jumps easily, but Neo falls in his first jump. Morpheus’ jump takes 4 s and Neo’s fall takes 7 s. Distance between the buildings as L and height as h and consider that Neo falls at the middle of the distances, L/2. If both 1 of them know a bit of...

Homework Statement Two projectiles are launched simultaneously from the same point above the flat terrain. The initial speeds of the projectiles are the same. Each projectile’s velocity makes the same angle with the horizontal. However, projectile A is launched above the horizontal and...

Homework Statement [/B] A simple pendulum is pulled sideways from the equilibrium position and then released. I figured this part out - Immediately after the pendulum is released, the net force acting on it is directed: it is perpendicular to the string (I REASONED THAT THE DIRECTION OF...

In general, one thinks of complex numbers as being absolutely required in Quantum Physics but as being optional in Classical Physics. But what about modern classical electromagnetic field theory (gauge theory) in which the electromagnetic field is coupled to the field of charged particles by...

Electric and magnetic parts of Maxwell's equations are kind of similar, so physical effects relating these properties have many 'dual' analogues - with exchanged places. For example in Aharonov-Bohm effect, the phase of charged particle depends on side of magnetic flux tube it comes through...

Homework Statement Two cyclists, Anant and Beth, are standing on a straight road a distance d=22.0 m apart. Simultaneously, they begin to move toward each other, Anant with acceleration a_A=0.2 m/s^2 and Beth with acceleration a_b=0.10 m/s^2. Just as they begin to move, a bee, sitting on...

There is a recent article (Optics July 2015) claiming violation of Bell inequalities for classical fields: "Shifting the quantum-classical boundary: theory and experiment for statistically classical optical fields" https://www.osapublishing.org/optica/abstract.cfm?URI=optica-2-7-611...

Homework Statement A cart roles down the track with an initial velocity vo. Because of falling rain, water starts filling the cart such that its mass increases linearly with time. The rain that has fallen on the track cause the wagon to experience a frictional force characterized with a...

Hello, I have already studied Griffith's book, Intro to Electrodynamics. However when I try Jackson's book, I find it a bit hard for me. My question is, what Maths and Physics texts (or specifically, chapters of texts) do you recommend, so that I would be best prepared for a graduate course in...

Hi, I'm currently taking thermodynamics in second year mechanical engineering. I read previous threads on here about good textbooks, and everyone seemed to agree that Cengel's book is really good. Its the book we use in class, but at times I don't think it explains everything as fully as it...

Probability to find a particle in some region of space is inversely proportional to velocity particle has in that region of space. Let's say we have two cases: one particle has velocity given by v(t)=v0*Cos(w*t), and other by v(t)=v0-v1*Cos(w*t), (v0>v1). Since particle spends more time in...

Hi guys - I was hoping people might have some topic ideas for a project I need to do in graduate classical mechanics as well as math methods. It needs to be a solution to an advanced problem or cover an advanced topic. I'm just looking for ideas that haven't been beaten to death. Any suggestion...

I was reading the book "Emperor's New Mind" by Roger Penrose which deals with understanding the nature of mind in the sense that it is algorithmic or not. In one of the chapters he explains that the deterministic world of the Newtonian Theory can still be non-computable. He explains this as...

From "Greenwood Donald T. - Classical Dynamics", Chapter 1, Section 1-4 (virtual work), Example 1-4: https://books.google.it/books?id=x7rj83I98yMC&lpg=PP1&hl=it&pg=PA26#v=onepage&q&f=false 1) There are 3 mass points of the same mass m moving on a plane (even if the text doesn't specify this)...

What is the consensus- Can the atom be considered a classical object if we managed to manipulate single atoms?

Hi guys I'm searching for a good undergraduate physics textbook on classical mechanics that might has an intro to langranzians and Hamiltonians, that I could tackle right now. I'm actually getting through apostol calculus 1 (just reached partial derivatives). I want it to be hard to follow ,but...

Hi, This might sound very basic and but i am just starting to learn physics. I an lecture by prof. walter lewin, he descibes the hunter and monkey scenario. The monkey jumps from the tree as soon as the hunter aims and shoot his gun. the bullet hits the monkey anyway. In calculating the time it...

Hello, I have a fundamental question about why state space control techniques are superior to the classical methods. I l know that you can control a system with multiple inputs and outputs for several states using state space control, however, can't the same thing be done in classical control...

I read in the Britannica Encyclopedia yesterday that Rene Descartes rejected the idea that a water pump works because nature abhors a vacuum, and instead said that it works "by the weight of the water which counterbalances that of the air". I have an idea of the two contrary concepts opposed...

Hello. I am currently reading on electromagnetism in university. However, I feel that I sometimes get lost in the the math in an otherwise excellent book (Field and Wave Electromagnetics by David K. Cheng), so I would like to ask, if somebody knows a good, steady resource for understanding the...

What I understood from Quantum Entanglement (QE), is that measuring the spin of one of two entangled particles in one location gives the spin of the other particle in other location no matter how far is the later. What I can also understand is that the same concept is applicable in the classical...

Hello everyone, I have a little problem with some transformation. I wonder how i can get that result. Can somebody explain it step by step? The " ' " means derivative. Thank you for your time ;)

This is a diagram of a pitot-static tube. My question is however not related to its applications but rather, what causes the liquid to rise up the static tube? The static tube is at right angles to the fluid flow. I understand that this is a very basic question but I can't seem to get my head...

A paper published in 'Gravitation and Cosmology', [21, 208 (2015)] and on today's physics ArXiv claims to have found a solution to the Wheeler-DeWitt equation that exactly corresponds to the classical evolution of a Friedmann model with appropriate matter/energy density: Exact Classical...

I just discovered the concept of phonons and the story of Brian Josephson (from reading "Sync" by Steven Strogatz). What the h...? So Phonon's are collective excitations of classical stuff made from QM ensembles, excitations made possible by the QM properties of the ensemble members? Are...

Hi all! I was directed (on another thread) to professor Leonard Susskind's first lecture on classical mechanics. I learned a lot from it, however he introduced a "rule" for "acceptable" classical fields/equations that I have a little trouble with. He explains classical mechanics as if you know...

Homework Statement A string wraps around a uniform cylinder of mass M, which rests on a fixed plane with angle θ. The string passes up over a massless pulley and is connected to a mass m. Assume that the cylinder rolls without slipping on the plane, and that the string is parallel to the plane...

We always consider the accelaration as a constant thing, while calculating the freefall problems. What if we try to calculate the real. I mean taking the accelaration GM/x^2. I tried it but i could not handle that integral(Just graduated from high school). I would be happy if you reply. Thank you

https://www.osapublishing.org/optica/fulltext.cfm?uri=optica-2-7-611&id=321243 "In our experimental test, we used light whose statistical behavior (field second-order statistics) is indistinguishable from classical, viz., the light from a broadband laser diode operating below threshold. Our...