Modern physics Definition and 249 Threads

I'm curious on just how much modern physics can be understood qualitatively, without equations. I know that people can understand F=ma with just words. For example, the acceleration an object experiences is directly proportional to overall force pushing or pulling on the object. The more force...

Homework Statement A football field is given in the following shape, where, ABCD is a square of side-length and AEB, CFD are semi-circular arcs. If an observer is moving with uniform velocity .along AB, what is the area of the football-field measured by the observer? ( is the velocity of light...

According to the equation, the graph of kinetic energy of emitted photoelectrons from a metal vs the frequency of incident radiation gives a straight line. My doubt is, what factors does the slope of this line depend on? I think it depends on the nature of metal used. Correct me if I am wrong.

Homework Statement The only things you know about the sample are: (i) it has some kind of cubic lattice, and (ii) it is a pure element. Identify the element in the crystalline sample. SC: R = 0.5a FCC: R = 0.25a√2 BCC: R = 0.25a√3 Distances from Bragg peaks: d1 = 0.2037 nm d2 = 0.1746 nm d3...

Homework Statement The separation between energies of an oxygen molecule is 2061 cm-1 (wavenumber). Treating the molecule as a simple harmonic oscillator whose fundamental frequency is related to its spring constant and reduced mass, calculate the spring constant for an O2 molecule. meff =...

Homework Statement Determine what colors of visible light would be absorbed by electrons in an infinite well, N = 3.1 nm. The effective mass for an electron is one-fifteenth of the standard electron mass. Homework Equations En = n2h2/(8mL2) E = hf f = c/λ The Attempt at a Solution E1 =...

Homework Statement Determine what colors of visible light would be absorbed by electrons in an infinite well, N = 3.1 nm. The effective mass for an electron in GaAs is one-fifteenth of the standard electron mass. Homework Equations En = πh2/[2*N2*me/15]*n2 L = nλ/2 Ψ = √(2/L)sin(nπx/L) The...

Homework Statement Estimate the ground state energy (eV) for an exciton in Si. εSi = 12 ε = 1.0359×10−10 Effective masses me* = 0.26me mh* = 0.36me effective mass = 0.15me Values of h 6.626×10−34 J⋅s 4.136×10−15 eV⋅s Values of ħ Units 1.055×10−34 J⋅s 6.582×10−16 eV⋅s Homework Equations E1 =...

An exciton is a bound electron-hole pair (in a semiconductor). For this problem, think of an exciton as a hydrogen-like atom, with a negatively charged electron and positively charged hole orbiting each other. The permittivity of free space (ε0) is replaced with permittivity of the...

I am currently in Honors Physics 3 which is the third introductory course of my physics degree program and covers modern physics beginning with special relativity. So far we have covered Lorentz transformations and velocity additions, relativistic energy and momentum, blackbody radiation, photon...

Homework Statement . An atom at rest can undergo radioactive decay, ejecting an electron at a maximum speed of 0.5c. If the atom in a particle accelerator is observed to produce an electron traveling at 0.75c, at least how fast must the atom itself have been moving? Homework Equations u0 x...

So I whilst understanding basics of some quantum phenomena like superposition, tunnelling, fluctuations etc I happened to watch the movie "Coherence" where there's a scientifically unsatisfactory reference to quantum decoherence. What exactly is this concept?

My college started physics course with light and blackbody radiation. I am facing difficulties in understanding relativistic energies, Compton effect and specific heats of multi atomic gases. Can you suggest a method for studying modern physics and suggest some good books for getting my concepts...

Physics is one of my most favorite topics, particularly Theoretical Physics. I have no formal education in Physics but I read quite a bit Physics material and also some Physics books. I have B.Sc. in Materials Science and Engineering. I like to discuss advanced physics ideas logically and...

Hello All, I am looking for suggestions for a junior-level Modern Physics textbook to read over the summer for the purpose of preparing me to take senior-level Quantum Mechanics in the fall. I have a solid Math background so a text that would possesses some level of mathematical rigorousness...

Good day, I made a purchase of this book by Bauer-Westfall, then realized I was looking for the Young/Freedman version. Did I get a good book or is this a paper weight? I am using this for self study from Newton to E&M along with Single Variable calculus. Any general opinions? Get another...

I'm finishing up my general physics 2 course (today actually) and I begin my upper division courses in Fall. I was wondering how you found general physics 2 compared to intermediate modern physics in terms of difficulty? I found physics 2 (basically introductory E&M at my school) more difficult...

Hi I'm an advanced undergraduate physics student and I'm currently searching books for my career project. The topic I selected is titled: Algebra and geometry in modern physics. So I'm currently looking for books that cover modern aspects of physics in a more mathematical approx. In specific I'm...

How to decide whether a particular topic is studied in classical physics or modern physics?

I'm not sure if I posted this in the right category, it's something that came up just after the quantum mechanics section so I just chose this one. I've come across something that I simply can not find an answer for on my own. I'm taking Modern Physics course and the last chapter is some...

Homework Statement It's in attachment Homework Equations E=hf. Where h= planks constant and f= frequency The Attempt at a Solution I know that the flux of a photon is (# of photons)/(sec m^2) I don't know the number of photos but I do know the frequency and power. E=(6.6261*10^(-34)) J•s *...

I have three courses to choose from, pick two. They are Introduction to Modern Physics, Mechanics 1, and Electromagnetism 1. Which should I choose? I have picked Modern Physics and Mechanics 1, but I almost want to do Mechanics 1 and Electromagnetism 1, but since it's my first semester at the...

Homework Statement In the experiment of Davisson and Germer (a) show that the second- and third-orderdiffracted beams cannot occur and (b) find the angle at which the first-order diffracted beamwould occur if the accelerating potential were changed from 54 to 60 V. (c) What...

Homework Statement Express the quantity ∂2/∂x2+∂2/∂y2 in polar coordinates. Homework Equations x=ρcosφ y=ρsinφ ρ=sqrt(x2+y2) The Attempt at a Solution This is my first post, so I apologize for any weird looking equations, etc. I know that this is not a difficult problem, but I just cannot...

I just thought about the critical concepts in mathematics and physics that arose in the last century: Goedel, Schroedinger, etc. My question is: Are there any physical theories that rely on the validity of the extended Riemann Hypothesis? I don't mean computer science, i.e. secure...

Hello, I'm Newbie here. Please be kind to me.

Homework Statement A K0 particle is unstable and has a mass of 8.87x10-28 kg. It can decay into π+ and π- particles, each of mass 2.49x10-28 kg. Suppose that a K0 is moving in the +x direction and decays by this process, with the π+ moving off at 0.9c and the π- moving off at 0.8c. a) What was...

I'm looking for suggestions of resources to learn introductory E&M and "modern physics" (I'm thinking relativity, QM, particle) conceptually. This learning is out of self interest. While my focus is for conceptual understanding, this doesn't mean any suggested resources should be devoid of...

Homework Statement I need to derive the equation related to the Compton Effect from the equations for momentum and energy conservation. Homework Equations (1) Compton Effect: λ' -λ = h/me(1-cosθ) (2) Conservation of Momentum (x-direction): h/λ= (h/λ')cosθ+γumeucosΦ (3) Conservation of Momentum...

Homework Statement If we take the average radius of the electron wave function in the ground state of hydrogen to be the Bohr radius, calculate the average potential energy of the electron due to the Coulomb interaction with the nucleus. State answer in eV. Homework Equations I think the...

It appears that I will be assigned to teach a modern physics course centered on quantum mechanics for those with almost no math background and I am searching for a suitable book. Essentially, this would be the modern physics equivalent of Paul Hewitt's Conceptual Physics book. I thought of...

I asked one time on this forum about bending space. If I take a paperback book and understand it as space instead of matter, and then bend it, it seems that the bent space moves into other space and that there is space from which it came. Now the idea didn't make any sense to me. Someone...

I've been wondering if space as understood by Newton, as an actual thing that contains matter, is relevant to modern physics. Has Newton's idea been disregarded? Is Aristotle's view that there is no space-vacuum now accepted? Thanks

Can someone recommend me a modern physics book, that includes introduction to all the different theories like quantum mechanics,quantum field theory,special relativity,general relativity,standard model,string,m-theory,supersymmetry,superstrings,quantum gravity,loop quantum gravity etc(if I...

Hi,I am new to this website and this is my first question. I just wanted to ask if irodov's chapter on light is of Ipho level or is it beyond that(that is it for 2nd or 3rd year undergrads) and Aldo what about modern physics. I would have no problem with that but if that is true then I will...

Hi everyone, I'm looking for an introductury book (or several books) on modern physics that explains the history and experiments the led to the understanding of the atom, the electron, avogadros number, Plancks constant, rutherford, quantum mechanics etc. I want an idea of how all the...

Hi - I'm doing an honors degree in physics by distance learning, having received my B.Sc around 20 years ago. I find there is a lot that is presented quite differently, and also stuff that I don't remember well enough - or not at all. So I'm looking for the fewest books that I can use to...

What math should a person know to THOROUGHLY understand everything in this textbook? (For refrence) cal2 (integration) cal3(mulit-variable) diffeq1(ode) diffeq2(pde) linealg vectorcalc realanal1 realana2 amazon link -http://www.amazon.com/Modern-Physics-Kenneth-S-Krane/dp/0471828726

Hi all, I have an undergraduate degree in Physics, but I've since specialized in more environmental applications of Physics. I've taken a few quantum Physics courses as part of my degree, but, if I'm being honest, what I took from those courses was more of a mathematical view of the field, such...

Hi all, I'm a Usman,a physics student from Pakistan .I have joined this forum to polish my physics skills and to share whatever I know about physics ,its principles and so many on......:smile::smile::smile::smile::smile::smile:

Homework Statement [/B]A wave is represented by the wave function: y = A cos(2πx/λ + π/3) for x < 0. For x > 0, the wavelength is λ/2. By applying continuity conditions at x = 0, find the amplitude (in terms of A) and phase of the wave in the region x > 0. Sketch the wave, showing both x < 0...

Hello everyone, I am working with my modern physics professor Dr. Parshar to make a pulse laser for my modern physics lab. I have to make an itemized expense report for the materials and all that. I need help figuring out what crystal or doped glass would be best to use, not super expensive...

How much additional material is in the extended version of Volume 2--how many additional chapters on what topics? Is it worth getting an extended edition copy for the additional modern physics material if one already has the non-extended version (and Young and Freedman 11E)?

Ok, currently I am studying a book called University physics with modern physics. I am only studying classical mechanics at the time. My question is, the modern portion part of it, is it about the same material taught in introductory modern physics class(state university) or do i have to get a...

It seems to me on the forefront that Artificial Intelligence research is more of the computer scientist's and mathematician's game, but I seem to recall reading a couple of books written by physicists on the subject as well (including Penrose's The Emperor's New Mind). Is this a popular trend...

Hello guys. I am fortunate that I have found this website and I have created an account just to ask one question. I asked this on yahoo answers as well but no luck. So here goes. I'm 14 years old and I love astrophysics. I have learn most of the basic stuff and I've also read A brief history...

The energy of photon is $$E=\frac{hc}{\lambda}$$ Now if we have an isotropic point light source of power P, Number of photons $$N=\frac{P}{E} = \frac{P \lambda}{hc}$$ Hence one can find the change in momentum and hence the force exerted by a beam or light sources. But let's say we keep an...

As the title implies, I am looking for a decent introductory modern physics text for self-study purposes. I'm a Biochemistry major, so this is partially for my own enjoyment and partially for preparation for Physical Chemistry II. I know that there are a lot of threads on this, but I always like...

I'm a first year physics undergraduate. I'm trying to look for some research opportunities as becoming a physicist is always my target. However, I simply have no idea how the current research is going on, and before I approach any professors I guess I should already have some basic understanding...

Hello people of the Physics Forums, this is going to be a bit of a long post, I apologize for that! I'm posting here to ask for some advice on how to prepare for my first sophomore-level modern physics class. I am feeling very nervous about this class because it is imperative I get top grades...