Classical Definition and 1000 Threads

Homework Statement A ray of light enters a glass block of refractive index n and thickness d with angle of incidence θ1. Part of the ray refracts at some angle θ2 such that Snell's law is obeyed, and the rest undergoes specular reflection. The refracted ray reflects off the bottom of the block...

In classical physics, charged particles induce electric field ##\vec{E}_c## around them. How do we interpret this classical electric field ##\vec{E}## in quantum mechanics. Is this just the vacuum expectation value ##\vec{E}_c=<0|\vec{E}|0>##? if so, it means ##<A>\neq 0##. This would lead to...

First-Order Extrema in "Classical Mechanics", Theoretical Minimum In the 3rd lecture of Classical Mechanics, 2011, by Dr. Susskind in his Theoretical Minimum series, he talks about calculating extrema, saddle points, etc. to "first order". "if you move a little bit, the potential is zero, to...

I mean many people try to abstract the classical world but isn't it just the accumulation of QM properties that build and break down what appears to be an obvious and intuitive classical world. Does QM outright contradict the classical world or does it explain the base fundamentals of our...

The classical physics developed by people such as Fraunhoffer and Fresnel seems to work very well at predicting the results obtained when observing interference and diffraction patterns. Quantum theory seems to work well also and can be used,for example when photons are sent one at a time...

I know this has been asked before but I am still not getting it. Does anyone know why a classical deterministic world with fixed positions emerges from the statistical distributions IE superpositions of the quantum mechanical world. Why am I nor my tv or dog not in superposition. There is a...

Greetings, Does anyone know of some good sources that explain classical perturbation theory, preferably using the Lagrangian formalism? The sources that I have seen more-or-less say, "write L=L_{0}+λδL, where L_{0} is an unperturbed, soluble Lagrangian, δL is the perturbation, and λ is a small...

In special relativity we have the invariant spacetime interval ds2 = dx2 - c2dt2. If we think about classical (non-relativistic) space and time as one spacetime in which the transformation between reference frames is given by the Galilean transformation, is there a corresponding spacetime...

In wikipedia it says that "Coulomb's law of electric forces was initially also formulated as instantaneous action at a distance, but was later superseded by Maxwell's Equations of electromagnetism which obey locality." I don't really understand in which sense Maxwell's equations solve the...

I am studying for the mechanics modules of A level mathematics under EdExcel.So far the books seemingly published to support the specifications aren't doing a very good job.The examples in the books don't tell the students how to solve problems in the exercises, which is a sheer let down.I want...

The definition of the Gaunt factor. Hello. I'm wondering about the Gaunt factor. I'm currently interesting in the spectroscopy in which the Gaunt factor is the correction factor to the classical cross section associated to the photon with electron thus the corrected formula is the identical...

I just took Physics I last semester, but I still feel there is so much more to learn about classical mechanics. I could work on 100 different problems involving binary stars, rockets, or rotating objects - but then a slight twist is thrown in on the problems, then something new to have to...

There's very few problems in Landau's books. I'm the kind of guy that properly learns material by doing tons of problems. Of course I can pull from other textbooks but there's the issue of different notation, extra material within chapters, etc... Does anyone know of a good resource that can...

From (Marion 5th ed. Problem 9-15) A smooth rope is placed above a hole in a table. One end of the rope falls through the hole at t = 0, pulling steadily on the remainder of the rope. Find the velocity and acceleration of the rope as a function of the distance to the end of the rope x...

Hello friends, Why does classical physics not follow a probabilistic nature? And why is conventional predicting absent at microscopic levels? I have searched a little including sites like physics.exchange but only see responses that are "classical physics fails to predict this" or "it cannot...

Hello, There has been lot many articles, write up(s) pointing out the difference between classical and quantum physics. Well, I know that there has been thousand and one articles written on the topic, but my point is to find out the basic fundamental difference. One point is quiet evident...

I am starting University in September, 2014. I have some knowledge already on classical mechanics as I took optional Applied Math courses (called Mechanics 1 and Mechanics 2) in my mathematics A-Level. I am also self-studying the book Classical Mechanics by Goldstein, Poole and Safko to gain a...

Homework Statement http://i42.tinypic.com/20adicz.jpgHomework Equations torque=rxF angular precession velocity=Δtheta/Δt assume that Δtheta=ΔL/Lsin(theta)The Attempt at a Solution I can conclude that the subsequent motion of the top will be an anti-clockwise circle about the origin but would...

Homework Statement a)Two people are holding the ends of a plank of length l and mass M. Show that, if one suddenly let's go, the initial acceleration of the free end (aD) is 3g/2. (7 marks). Moment of inertia, I, of the plank about its centre of mass is given by I=1/12(Ml2) b)Show...

Homework Statement suppose every charged particle carried electric and magnetic charge in the universal ratio Gk/Ek=a. is there another way of looking at this situation in which we would be unaware of magnetic charge?

Recently I have been troubled by several things which have been stated in my school physics classes, mainly concerning the classical kinetic energy formula and other formulae derived from it (as well as the 'Work Energy Theorem'). The classical formula for kinetic energy '(mv^2)/2' was first...

Homework Statement It's not a direct question, but it's an implied part of a larger question: can classical waves experience simple harmonic oscillator potentials, like a mass on a spring does? Homework Equations The Attempt at a Solution I'm thinking no, since I can't come up...

Dear all, I'd like to specify meaning othe relaxation phenomenon on example in some classical system. For example in Wiki I found example of dampled oscilator where the relaxation time ( the time is needed for the system to return to the equilibrium fluctuation pattern) add exponential decay...

"The" Classical Path, QM Path Integrals and Paths in Curved Spacetime Hey Guys! I've got an exciting question! It's been burning on my mind for years, but I think I can formulate it now. It's not so much a specific question, but rather a physical story which perhaps this thread can uncover...

Homework Statement A mass m1 is attached to a fixed spring on a horizontal surface and attached across a pulley (ignore the pulley mass) to another freely hanging m2. Write the Lagrangian in terms of a single parameter. Find the equation of motion and determine the frequency of oscillation...

I was recommended this by a friend. I'm going to get K&K but I was wondering what you thought of this book if you have read it. Is it good for beginners? Comprehensive? General comments? Thank you, Tridian

My understanding is that a classical idealized particle, moving in one dimension, with momentum p and kinetic energy T comes into contact with an infinite step-function potential V, there will be an (instantaneous) elastic collision - the particle's momentum becomes -p, so its energy remains...

Hi guys, Just ran into a debate with friends about this topic. We were discussing whether the scope of pure sciences (in particular, Classical Physics)decreasing over time? Has it decreased till date? The fact that newer questions posed now a days are tougher than the times of Newton and...

John Taylor "Classical Mechanics" Chapter 5, Problem 29 Homework Statement An undamped oscillator has period t(0)=1 second. When weak damping is added, it is found that the amplitude of oscillation drops by 50 percent in one period r1. (the period of the damped oscillations defined as time...

Homework Statement A massless wire hoop of radius R is rotating in a horizontal plane about its central point with constant velocity ω. There is a tube of negligible mass pinned across the hoop on a line passing through the central point. Inside this tube is a spring of negligible mass with...

Homework Statement Consider the multiplicity of a classical gas of N non-interacting molecules (not necessarily monatomic). Since they don't interact,their positions are not correlated, so the multiplicity of each will be simply proportional to the volume, with the result that the total...

Wheres the limit between quantum mechanics and classical mechanics. I mean,when can I expect quantum behavior on a system, is it depends on the system size?Tempature? Something else...and if so what are the numbera for those limits. As we know in nature everything is continuous, so, the...

Homework Statement a particle of mass m moves on the orbit r= a cos(θ), a>0. Find the force acting on the particleThe Attempt at a Solution I had this formula in my notebook:U(r)= E-(L^2/2mr^2)(1+(1/r^2)(dr/dθ)^2) Using it I got U(r)=E-L^2a^2/2mr^4 and F(r)=-dU/dr= (-5L^2a^2/2mr^5)...

John Taylor "Classical Mechanics" Chapter 3, Problem 7 1. Homework Statement [/b] The first couple of minutes of the launch of a space shuttle can be described very roughly as follows: The initial mass is 2x10^6kg, the final mass (after 2 min) is about 1x10^6 kg, the average exhaust speed is...

Consider the classical wave equation in one dimension: \frac{\partial^2 \psi}{\partial x^2}=\frac{1}{v^2} \frac{\partial^2 \psi}{\partial t^2} It is a linear equation and so the set of its solutions forms a vector space and because this space is a function space,its dimensionality is...

Homework Statement When engine was turned off,boat with mass m was moving with speed v_0. The force of friction F=-\alpha\nu-\betav^2. How long it would take to drop speed of boat 3 times? Find the distance which the boat will travel in this time? Homework Equations The Attempt...

I've been reading through the posts on this forum that deal with the photoelectric effect as evidence for the quantization of the EM field. In all of the introductory texts I've read, the cut off frequency and the dependence of the photoelectron energy on the frequency of the light are...

Why is it that in the damped simple harmonic equation, the force constant can take on all values, but the force constant corresponding to the classical harmonic oscillator potential in the Schrodinger equation can only take on discrete eigenvalues?

Hey all, suppose there's a particle with Potential Energy : U(x) = A*[ x^(-2) - x^(-1) ] , where A is a constant. I'm supposed to find the energy required to make the particle go from periodic movement to unlimited movement. First thing I did was U '(x) = 0 to find the balance points, now...

Hi! Is there a way to calculate the classical orbital elements for a satellite or space shuttle around Earth using Matlab? I would like to get started with it since it is something that I've not tried before. so plese help Best regards

Homework Statement I'm so confused please help :\ Show that the contribution to the total energy from molar internal energy Um reverts to the classical expression at high T.Homework Equations Classical: Um = 3NakT Quantum Um = 3NAhv/e^(hv/kT)-1 The Attempt at a Solution Manipulating...

What type of physicist works in the field of Classical Mechanics? And yes, this does encompass the general theory of relativity.

Homework Statement If anyone could help me with this classical mechanics exercise I would be very grateful! The exercise is as follows: The muon (μ) is a particle with mass mμ=207me, with me being the electron mass. The pion (∏) has a mass of m∏=273me. The pion can decay into a muon...

The below picture is from my book's derivation on the equations describing waves in matter. But problem is: I don't understand the solution of the differential equation - or "difference" equation (whatever that is). How is it solved with the proposed solution? If I plug it in I don't get...

Homework Statement A block at t=0 is at the bottom of the plane and is projected up an inclined plane with initial speed v0. The plane's acute angle is θ above the horizontal, and the coefficient of friction is μ between the block and plane. Find the time (t) and velocity (v1) of the...

Am I "ready" for Classical Mechanics? Hello again, PF. I have a question about the Classical Mechanics course I'm taking this coming fall. Thanks to having a few cruddy enrollment times in the past year, I've been taking my courses a bit out of order, but without any problems or conflicts...

According to my prof, increasing intensity of the light source in a photocell for the photoelectric effect does not increase the kinetic energy of photoelectrons emitted. Instead, the number of electrons emitted (and current) increases. Changing the colour of the light causes an increase in...

Hi, I am trying to gain a better understanding of the classical model of electrodynamics, so what I mean by this is, using the idea of dipoles and electron movement to understand electrodynamics. More specifically, I'm studying plane waves, and I can't understand why when a plane wave hits a...

Homework Statement Problem 27 Experiment needed first: The hallmark of inertial ref. frames is that any object subject to 0 net force travels in straight line at a constant speed. Consider the following experiment: I am standing on the ground (which we shall take to be an inertial frame)...

EDIT: Okay I don't expect an answer for this because of my crappy attempt at LaTex, i'll work on making it look prettier sorry Homework Statement If the kinetic energy of a particle is equal to twice its rest energy, what percentage error is made by using p = mu for the magnitude of its...