Relativistic Definition and 1000 Threads

Hi, I'm trying to get the relativistic kinetic energy, ## T ##, from the work expended, ## W ##, (assuming that the body is at rest initially) and I'm doing it like this (in 1D): \begin{equation} W = T = \int F ds = m \int \frac{d(\gamma u)}{dt}u dt = m\int u d(\gamma u) \end{equation} Where...

Homework Statement The ##B^+## meson decays through the weak interaction. One of its decay channels is . If a ##B^+## is traveling with a total energy of 9.90 GeV, calculate the range of possible energies the produced may have. (i.e. determine the minimum and maximum values of its energy.)...

Homework Statement Hi I am supposed to calculate the distance traveled by a particle that is uniformly accelerated with acceleration equal to the Earth's gravity (i.e. a=9.81m/s^2) after 1, 10 and 100 years proper time. Homework Equations We derived in class the four vector which describes the...

Consider two equal masses, m, are placed on two identical scales in a uniform gravitational field. If one of the masses moves with relativistic speed, does the moving scale read mg or γmg? Why? It seams that people used to call γm the relativistic mass where m is the rest mass. However, more...

I am currently reading Zwiebach and intend on reading Becker and Polchonski afterwoods. In chapter 4 he slves a partial differential equation with the Dirichlet and Neumann BC. My question is what the difference is between the two BC.(BC=Boundary conditions). Thanks for any help.

The question is as follows: We can define the rapidity, y, of a particle with respect to the x axis y≡tanh-1βx. Show that under a Lorentz transformation by rapidity yB y'=y-yB The Attempt at a Solution I started by working backwards (sorry if the LaTeX does not work $$...

Hi, I have one question, The rel. dofs are: g_* (T) = \sum_{i=bosons} g_i \Big( \frac{T_i}{T} \Big)^4 + \frac{7}{8} \sum_{j=fermions} g_j \Big( \frac{T_j}{T} \Big)^4 Before the neutrinos decoupling, the relativistic degrees of freedom are: g_*=g_\gamma + \frac{7}{8} (g_e + g_\nu)= 10.75 This...

On the ISS, special relativity dictates the station's clocks run slower than clocks on Earth because of the high velocity, but general relativity dictates that the station's clocks run faster than clocks on Earth because of the lesser gravity. Which effect is predominant, and do the station's...

Let's imagine say, a spaceship is going through space at 99% the speed of light. Relativity says (to my understanding) that as the spaceship increases in speed it's mass will increase and it shall also get slightly shorter. Let's assume that energy isn't a problem, should the spaceship continue...

Statement 1 - Let's assume a charged particle emitting radiation isotropically in it's rest frame, when boosted in another frame we get the relativistic beaming effect. This results in anisotropy of the radiation emitted by the charged particle in the boosted frame. Statement 2 - But a particle...

PROBLEM SOLVED - the worked example I was referring too was wrong :/ ---------------------------- Hello, I've been stuck on a question in one of my SR problem sets for some time now, and managed to find a worked solution to a similar problem online. I've attached an image of the problem (the...

PROBLEM: Show that Special Relativity predicts a precession of π(GMm/cl)2 radians per orbit for any elliptic orbit under a pure inverse-square force. where G is gravitational constant, M is mass of larger body, m is mass of smaller orbiting body, c is speed of light and l is angular momentum...

I have never done relativity before, my uni professor isn't good enough and I can't understand a word he says, he's all over the place. Anyway I missed a week due to being sick, and I just can't catch up, I am struggling to find any textbooks that have similar notation or help me solve...

I have been recently trying to derive the Einstein tensor and stress energy momentum tensor for a certain traversable wormhole metric. In my multiple attempts at doing so, I used a coordinate basis. My calculations were correct, but the units of some of the elements of the stress energy momentum...

What are the advantages of RQM against QM? If RQM is more accurate that QM then why use QM (yet only if it is) or better said if it is more complete? I read Paul Diracs lectures 1-4 and he talked about relativistic quantum mechanics and quantization of flat and curved spaces in lectures 3-4, so...

Homework Statement For a particle traveling near the speed of light, find the first non-vanishing term in the expansion of the relative difference between the speed of the particle and the speed of light, (c-v)/c, in the limit of very large momentum p>>mc. Hint: Use (mc/p) as a small parameter...

In case of a relativistic particle, one can try to minimize the length of the worldline of the particle, thus write the action as: S = -m \int_{s_i}^{s_f} ds = - m \int_{\tau_i}^{\tau_f} d \tau ~ \sqrt{\dot{x}^{\mu}(\tau) \dot{x}^{\nu} (\tau) \eta_{\mu \nu}} Where the minus is to ensure minima...

Homework Statement Good morning/ afternoon I have a doubt about relativistic collisions, any help will be welcome. Consider the process of annihilation electron-positron to two photons. Calculate in the centre of mass system the wavelength of photons produced using momentum of e+e-...

Homework Statement Two relativistic particles "L" and "R", each of rest mass ##m_0##, are moving at speed ##v## towards each other (in the frame of an observer). They collide squarely and are stationary afterwards. (a) From the perspective of one particle, what is the oncoming speed of the...

Hi, I'm trying to figure out exactly what colors a white light (i.e. the Sun) would look like to an observer traveling at varying relativistic velocities. Yes, moving away from it - red shift. Moving towards it - blue shift. In more detail, the human eye has a limited varying-amplitude...

As the title of the thread suggests, I'm interested in estimating the velocity distribution of neutrons in neutron star cores. Putting T ~ 10^12K gives v ~ 15%c or more under Boltzmann statistics. Could someone provide more information or a second opinion on this estimate? Thanks.

Hey all, Simple question yet it creating a lot of confusion in me and I need some clarification. This is an example given in a book I'm reading and I just don't understand one piece of it. In the S frame a completely inelastic collision between two particles traveling at each other at speed u...

Consider the Spinor object for an electron. Are the non-relativistic and relativistic (Dirac equation) Spinor objects, from a mathematical point-of-view, identical? Thanks in advance.

Homework Statement An electron accelerated from rest through a potential difference V acquires a speed of 0.8c. Find the value of V. Homework Equations E=(gamma)mc^2, E=Vq The Attempt at a Solution For this I related the two equations above and chose a value of m=0.5MeV for the electron and...

Can someone either derive or point me to a derivation of Møller's formula for the relativistic minimum radius of a rotating body? I've been searching for about an hour and it's driving me crazy! The only "minimum radius" equation I've seen imposes the speed limit c on a classical rotating body...

Homework Statement What is the kinetic energy of an electron with a momentum of 40 GeV/c? The Attempt at a Solution Kinetic energy involves velocity of the particle so my first thought was to write momentum in terms of velocity. p = \frac{mv}{(1-(v/c)^2)^{1/2}} p^2 = \frac{(mv)^2}{(1 -...

Homework Statement Show that 1/2mγv^2 does not give the correct kinetic energy. Homework Equations 1/2mγv^2 γ = 1/(sqrt(1-v^2/(c^2))) The Attempt at a Solution Well, since the classical mechanics version of kinetic energy was the integral of momentum with respect to v, I felt I could...

Homework Statement In a nuclear reactor, each atom of uranium (235 amu) releases about 200 MeV when it fissions. What is the change in mass when 1.0 kg of uranium 235 is fissioned?Homework Equations E = mc2 The Attempt at a Solution I found the energy released per kg based on the numbers...

1. A particle of mass M decays from rest into two particles. One particle has mass m and the other particle is massless. The momentum of the massless particle is... 2. Ei = Ef, Pi= Pf 3. This is a GRE practice problem. I can solve this problem using the old method as listed in the step 2, but I...

Can anyone answer this question? What you would see while watching a stationary clock that you are moving directly away from at a constant relativistic velocity? Yes, any practical clock would immediately shrink to a tiny point an instant after you passed it. So, either assume a really huge...

Pardon my elementary questions, but: Why is it that photons can only travel at the speed of light? I know because they have zero rest-mass it is only possible for them to travel at c, but is there some mathematical reasoning to this through the mass and momentum equivalence equation...

Homework Statement A Higgs boson has mass 125 GeV/c2, decaying into a pair of Z bosons, mass 91 GeV/c2. In the lab frame, one of the Z bosons is at rest. Determine the kinetic energy for the other Z boson in this laboratory frame. Homework Equations E = γmc2 γ=1/√(1-β2) The Attempt at a...

For a long time I have studied and read about whether the photon has mass. On this forum, I could find a link to a document by Gary Oas: On the abuse and use of the relativistic mass. http://arxiv.org/pdf/physics/0504110v2.pdf Oas' paper tells about an investigation done to 164 students...

Homework Statement Suppose a circle of radius 'b' is set in motion.Calculate the relativistic speed parameter β(=v/c) such that the circle is seen as an ellipse of semiminor axis 'a' and semimajor axis 'b' where a <b.3 marks. Homework Equations L=L0/γ The Attempt at a Solution...

Reposting to this section of the forum instead of the Introductory Physics homework section. So let's say a guy travels at 0.5c in a spaceship from planet 1 to planet 2. Am I right in saying that: proper time = time measured inside space ship proper length between planets = length the...

I'm trying to reconcile the two relativistic mass equations and I 'm getting different results as I push the velocity towards c. In the first equation, E=mc^2/√(1-v^2/c^2), I'm getting that E approaches infinity as v approaches c. In the second equation, E=√(m^2c^4+p^2c^2), I'm getting...

Does this solution mean anything ?

I feel I understand relativistic velocity addition fairly well. However, the way I usually see it modeled is with two travelers moving in the same direction. Bob is in a spaceship traveling at 0.6c and shines his flashlight in the direction of travel. An inertial observer, Alice, relative to...

Hi Just wondering about the orbital path of a high speed particle - eg electron in orbit. Is it length contracted? Then how do we manage nλ=2.π.r ? Neil

Ok, so if I were to travel towards a black hole at close to c, would the event horizon become visible? Let us assume there are no stars, CMB, or any other luminous body in the universe.

I am curious about recent progress in relativistic Bohmian mechanics. Finding a review is proving difficult (The closest I can find is a conference paper by H. Nikolic). My understanding is a set of dynamical variables are identified as "real" (beables), and their (usually deterministic)...

hi fellas, I have been working on Chandrashekhar limit, and I found a mass-radius relationship for the nonrelativistic fermi gases using this formula and i got the graph of this R=((18pi)^(2/3))/10 *H^2/(GmM^(1/3) ) (0.5/n)^(5/3) where H=(6.63*10^-34)/2pi G=6.67*10^-11 m=9.11*10^-31...

How can someone think of the neutrinos as non relativistic? OK I understand for example that the neutrino temperature is very small even compared to their masses... but at the same time I find it non trivial to think of very light particles with energies: E≥1eV non-relativistic... How can the...

Hi all, Is it possible to derive the equation p = ymv, and hence based on this, kinetic energy formula, without referring to 4-vectors or 2-dimensional collisions, that is derive it in one dimension? I tried this website/pdf but the mathematics is beyond my understanding. So could some one...

Astronauts on a long space journey are playing golf inside their spaceship, which is traveling away from the Earth with speed 0.6c. One of the astronauts hits a drive exactly along the length of the spaceship (in its direction of travel) at speed 0.1c in the frame of the spaceship. What is the...

I was just thinking about this, and from a perspective of an inertial frame, it's easy to see how distances contract, times dilate, simultaneity varies between observer and the speed of light is exactly c in each case. But what about non-inertial frames? In the presence of gravity almost...

Homework Statement Suppose you want to make a velocity selector that allows undeflected passage for electrons whose kinetic energy is ##5x10^4eV##. The electric field available to you ##2x10^5V/m##. What magnetic field will be needed?Homework Equations ##u=\frac{E}{B}## u is velocity, E is the...

Relativistic frequency shift of satellite signal Homework Statement An Earth satellite used in the Global Positioning System moves in a circular orbit with period 11 h 58 min. (a) Determine the radius of its orbit. (b) Determine its speed. (c) The satellite contains an oscillator producing...

Hello to everyone! I cane across this problem and since I have no training in SR I can't solve it on my own, That is why I would very mutch apprecitate any help I could get. The problem: A photon and a spaceship simultaneously start at planet A and the travel in paralal towards planet B. The...

Hi everyone: I just started to learn special relativity but totally being confused about "velocity", "momentum" and "force". 1. The relativistic momentum is defined by "rest mass * ordinary velocity * gamma". There are 2 kind of explanations. The first one is combining "rest mass * gamma"...