Relativistic Definition and 1000 Threads

  1. O

    Why Does Integrating Relativistic Kinetic Energy Lead to Different Results?

    I am doing the integral DK = ∫pdv = mv/(√1-v2/c2)dv , in the same way as they do the ∫Fds = ∫mvdv if you separate the integrals. Where is my mistake and istead of (γ-1)mc2 I get -mc2/γ . I know that I am mistaken, I did see some equations but I don't get the 'theoretical' part.
  2. T

    Is the Sun invisible at relativistic speeds?

    At which speed does the Sun disappear from the visible part of the spectrum if I were to travel towards it at high speed? Let's assume there are no other stars in the visible universe and I'm a few light-years away.
  3. C

    Magnetic Fields with Relativistic Motion of Electron

    Homework Statement There is a magnetic field given by the equation \overrightarrow{B}=B_{0} \hat{x} \sin\left(2\pi z/L\right). If there is a 10^7 eV electron going in the \hat{z} direction (moving at a relativistic velocity), a mag. field strength of 0.1T, and a mag. period of 0.01m, what...
  4. G

    Feynman's vs wiki's relativistic resultant

    In Feynman Lectures on Physics vol 2 pg.13.6-13.10 develops the equations for a current carrying wire and a moving charge ( negative test charge) with the same velocity as the electrons in the current. He looks at this situation from two reference frames, 1) the wire still and test charge and...
  5. S

    Interpret Relativistic Momentum: Facts & Popular Opinion

    I understood the derivation of relativistic momentum, but I am uncertain of how to exactly interpret it. One could interpret the arrangement of terms to be relativistic mass times velocity, and this appears to be in agreement with data from particle accelerators (or so I have been led to...
  6. C

    Magnetic field relativistic effect

    Hi Forum, It is said that the Magnetic field is a relativistic effect. I went to the Feynman lectures on Physics and found an example based on the force a charged has when moving at speed v next to a conductor with a current density J. I understand that the framework at rest uses a magnetic...
  7. U

    Relativistic collisions - different frames, threshold energy

    Homework Statement (a) Show that E2 - p2c2 is a Lorentz invariant, where E is the total energy, p is the momentum, c is speed of light. (b) In the lab frame, an utlra-relativistic electron with γ = 100 collides head-on with a photon of energy E. Find the threshold energy E required to...
  8. S

    Calculating Relativistic Mass of Rotating Object

    Hi. I need to find the mass (relativistic mass?) Of an object in rotation. Say I have a string with a small rock tied to the end. The relevant variables are: A) The circumference of the weights path. B) The weight of the rock itself. C) The revolutions per minute that B...
  9. michael879

    Are classical models of electrons with spin limited by the speed of light?

    Ok so I have two very different questions, both closely tied to the concept of relativistic angular momentum. Question #1: Why do people claim there is a minimum radius for a classical model of electrons with spin? The typical argument is that if the radius were to fall below some minimum...
  10. P

    Rutherford Scattering, relativistic

    Homework Statement Asked to calculate the relativistic correction, to the differential scattering cross section which is given by the equation below in terms of E, E0 and θ where E0= .511 MeV. with 100MeV electrons from an Au nuclei at certain angles θ. Homework Equations Relativistic...
  11. V

    Equation of motion in tensorial form (relativistic)

    Homework Statement How does one solve the tensor differential equation for the relativistic motion of a partilcle of charge e and mass m, with 4-momentum p^a and electromagnetic field tensor F_{ab} of a constant magetic field \vec B perpendicular to the plane of motion...
  12. Z

    How Long Does It Take for One Rocket to Pass Another at Relativistic Speeds?

    I do have a specific example/problem, but my actual question is more so conceptual (I'm sure that seeing someone confused by relativity is a first around here!). The problem: Two rockets are each 1000m long in their rest frame. Rocket Orion, traveling at 0.900c relative to the earth, is...
  13. T

    Radiated energy by decelerating (relativistic) point charge

    Homework Statement A point charge q is moving relativistically with constant speed ##\beta## along the x-axis. At t = 0 a constant decelerating force F is applied in opposite direction of its velocity. If the charge stops after traveling a distance d, find the total radiated energy...
  14. T

    Conservation of Relativistic energy and momentum

    I was reading through this article http://en.wikipedia.org/wiki/Four-momentum#Conservation_of_four-momentum It says "The conservation of the four-momentum yields two conservation laws for "classical" quantities: The total energy E = P0c is conserved. The classical three-momentum p is...
  15. E

    Deriving Relations in Relativistic Mechanics: dE/dt = dm/dt?

    I am still trying to derive all the relations in relativistic mechanics, and have narrowed one of my problems down to the following. If E = m (c=1), then shouldn't dE/dt = dm/dt ? The left side of that equation is the work done on the particle per unit time, or the velocity vector -dot- force...
  16. Z

    Relativistic Kinematics conservation of energy

    Homework Statement A particle with rest mass m_{0} and kinetic energy 3m_{0}c^{2} makes a completely inelastic collision with a stationary particle of rest mass 2m_{0}. What are the velocity and rest mass of the composite particle? Homework Equations T = (\gamma - 1)m_{0}c^{2} = E -...
  17. A

    Magnetic Fields of a Relativistic Charged Particle

    Where can I find a picture of the magnetic field lines produced by a charged particle moving near the speed of light? Is there a formula for the strength of B and direction of field lines as v --> c? Does this equation reduce to Ampere's right hand rule for a moving charge's ability to create...
  18. R

    Relativistic Momentum: 880kg Spacecraft at 1/2 C

    Hi everyone so I have a couple of questions I would like to get some help on. The first one is as follows: A 880-kg spacecraft is traveling forward at 1/2 the speed of light. What is the relativistic momentum? I know the equations I am just having trouble plugging the numbers in I think. Thanks
  19. D

    Conceptual portion of Relativistic Jets Problem

    1. The full problem statement, all variables and given/known data The problem can be found http://www.astro.umd.edu/~chris/Teaching/ASTR498E_Spring_2006/homework5.pdfif any of my description is lacking. I have solved successfully part a), most of b), and c) for the problem, but part d)...
  20. E

    Relativistic Forces: Confirm Resnick's Results?

    Am working my way through relativistic mechanics, and one force transform (Fx) I derive has an extra factor in one term. Of the many textbooks I have, the only one that presents those equations is Resnick – Introduction to Special Relativity. And it doesn’t look like even he derived them, but...
  21. J

    The relativistic mechanics of spinning discs

    These are kind of my own thoughts. Does the theory of relativity disagree with any of these? When a spinning disc is heated, the spinning rate decreases, and spinning energy is being converted into additional heat. When a spinning disc is accelerated linearly, the spinning rate decreases, and...
  22. W

    Time difference of events when moving at relativistic speeds

    Homework Statement Lets say that Planet A and Planet B are moving in the the same inertial reference frame. The distance between them is 8.3 light minutes. Event A occurs on Planet A at t=0, and Event B occurs on Planet B at t=2 minutes. If an observer is traveling from Planet A to B at 0.8c...
  23. P

    Does Relativistic Mass Affect Scale Readings Inside a Moving Rocket?

    From relativity, if a rocket moves close to c, then its mass increases along with everything inside the rocket. Now what if there was a scale inside the rocket? Would the scale read a higher value? I assume the scale should stay the same because if it didn't, then you can do an experiment...
  24. K

    Relativistic vs. non-relativistic quantum mechanics

    Would one consequently use relativistic QM or in some cases use the non relativistic postulates when dealing with a problem in the same that classical physics are used frequently when one deals with objects traveling at speeds much lower then the speed of ligth??
  25. Z

    MTW, Chap19, Stationary relativistic Vs Weakly gravitating source

    hello, in MTW Ex 19.1, it was considered a Weakly gravitating body whereas in Ex 19.3, a Stationary relativistic source. What relativistic means here ? does it mean the source is very dense and massive ? or does it mean it is rotating at near the speed of light ? Can I specify the mass as the...
  26. B

    Equation of Motion for a Point Mass Falling into an Infinitely Small Black Hole

    Say I have a special type of black hole, an infinetly small one. I am standing still in deep space and i let a point mass to fall. What is it's equation of motion? I'm interested in the equation itself not just an explanation. It should be sth like this x=f(t).
  27. S

    How Can We Calculate Relativistic Velocity for an Interstellar Journey?

    I saw the following scenario on an episode of Cosmos: An interstellar spaceship accelerates at 1g for the 1st half of a journey to a distant star and then decelerates at 1g for the 2nd half. So with constant acceleration, the velocity would go beyond c at some point, which is not possible. So...
  28. I

    Relativistic energy/momentum conservation problem

    Homework Statement A particle of rest mass m0 moving at a speed of 3/4 c collides with a same-mass particle at rest and they stick together to form a composite particle. What is the rest mass of the composite particle and what is its speed? Homework Equations E = \gamma mc^2 p = \gamma mu...
  29. J

    I Relativistic Explanation for the Unipolar Generator

    Hello All, I was recently looking into explanations for the operation of Faraday's unipolar generator and came across the following article, titled "The Unipolar Generator, A Demonstration of Special Relativity" published by a professor at the University of Maryland...
  30. Hercuflea

    Relativistic mass for an interstellar craft

    So there have been some theoretical designs for ships in the past that would be used for interstellar missions, i.e. Daedalus, Ramjet, Orion, etc. that may send ships to near relativistic speeds. I think daedalus had a max. speed goal of around .1c. My question is do you think that...
  31. Saitama

    Energy of relativistic particle in LHC

    Homework Statement (see attachment) The proton charge is ##1.6 \times 10^{-19} C## and the speed of light is ##3 \times 10^8 m/s##. The proton's mass is not necessary in this problem. Homework Equations The Attempt at a Solution The particle revolves in a circular path, hence...
  32. G

    Does Relativistic Mass Affect Weight and Gravity?

    Imagine you're standing on a long, straight and smooth road. You place a block on the road. The normal reaction force acting on the block is equal to its weight. Then you give the block a little push. Since the block is moving from your frame, its relativistic mass increases. Will its...
  33. F

    Conservation of relativistic momentum and energy

    Homework Statement The K0 meson is an uncharged member of the particle "zoo" that decays into two charged pions according to K0 ---> π+ + π-. The pions have opposite charges as indicated, and the same mass, mπ=140MeV/c^2. Suppose that a K0 at rest decays into two pions in a bubble chamber in...
  34. H

    What is the Mass and Speed of the Second Object in a Relativistic Collision?

    Homework Statement A 3.000 u (1 u = 931.5 MeV/c2) object moving to the right through a laboratory at 0.8c collides with a 4.000 u object moving to the left through the laboratory at 0.6c. Afterward there are two objects, one of which is a 6.000 u object at rest. A) Determine the mass and...
  35. W

    How does the Relativistic Doppler Effect Affect Observed Wavelengths?

    Homework Statement A light source moves away from an observer at a speed vs that is small compared to c. show that the fractional shift in the observed wavelength can be approximated by \frac{\Delta \lambda}{\lambda} \approx \frac{v_2 }{c} Homework Equations f' = \frac{\sqrt{1+ \frac{v}{c} }...
  36. A

    Relativistic index notation del-operator

    Hi, I've been wondering about this forever and I finally decided to ask on the forums. In relativistic index notation (with c= \hbar =1) with the minkowski metric g\mu\nu=diag(1,-1,-1,-1), the 4-vector x^{\mu}=(t,x,y,z)=(x^0,\vec{x}), and with the del operator defined as \partial_{\mu}\equiv...
  37. D

    Help with relativistic momentum question

    Homework Statement a Pion traveling at 0.93c decays into a muon which travels in the same direction and a neutrino which travels in the opposite direction. Use conservation of energy and momentum to find the energy of the muon as determined in the rest frame of the original pion. You should...
  38. V

    Restricting RMS Speed of Molecules to Comply with Relativity

    How can we restrict the RMS speed of molecules to comply with relativity? They obviously can't go at or faster than the speed of light. If you are dealing with particles inside of very hot stars for example you may get very high erroneous speeds. v = \sqrt{\frac{3KT}{m}} How could...
  39. G

    Understanding why Einstein found Maxwell's electrodynamics not relativistic

    I'm trying to understand exactly why Einstein considered Maxwell's electrodynamics to be non-relativistic. As I read Maxwell's paper, it seems to me that it is concerned only with relative motions. I'm thinking that the problem must be with the stationary ether proposed by Lorentz, for then...
  40. D

    Help with relativistic momentum question

    Homework Statement a D meson is at rest and decays into a Kaon and a Pion. The Kaon moves with speed 0.867c and has a mass of 0.494 GeV/C^2. The pion has a mass of 0.140 GeV/C^2. use conservation of momentum to calculate the speed of the Pion. Homework Equations Relativistic Momentum P =...
  41. V

    A thought experiment on relativistic Electrostatics

    Here is a thought experiment on Special Relativity involving charges which are rest with respect to each other. Consider a configuration of charges as shown in the image. Four identical charges (q) are placed at the corners of a square with an opposite charge at the centre (Q). The value of...
  42. K

    Understanding the Relativistic Velocity Addition Formula

    Homework Statement In this thread the author performs the following calculation under "method 1": v+dv=\frac{v+dv'}{1+vdv'}=v+(1-v^2)dv'\implies dv'=\frac{dv}{1-v^2} He's set c=1 so the second expression is the relativistic velocity addition formula. What I don't understand is how he gets the...
  43. K

    Relativistic Electron/Positron collison.

    Homework Statement In an electron positron collider, an electron and a positron are collided such that their momenta in the lab are equal and opposite. In such a collision, the electron and the positron annihilate and produce a muon and an antimuon. The rest mass of a muon is 106MeV/c^2...
  44. W

    Solve relativistic velocity in terms of momentum (vector equation)

    Given the formula \vec{p}=\frac{m_0}{\sqrt{1-\frac{|\vec{v}|^2}{c^2}}}\vec{v}, I'd like to make \vec{v} the subject, so I can do a numerical approximation for some relativistic motion problem. I want to treat it as a vector equation, but since it is non-linear, the only way I can think of is to...
  45. B

    Speed of a Relativistic Particle?

    Homework Statement Particle track detectors are used to measure the speed of particles if the lifetime of the particle is known. Particle X has a lifetime of 256.2 ps. These particles are created in an experiment inside the detector by a given reaction. The particles leave 21.8 cm long...
  46. S

    Feynman Factors & Relativistic Scalar Propagator

    Hey again, I have a question on a couple of things related to feynman diagrams but also the relativistic scalar propagator term. First of all, this interaction: The cross represents a self-interaction via the mass and characterised by the term: -im^2, is this just some initial state...
  47. S

    Feynman diagrams and relativistic propagators

    Hey again, I have a question on a couple of things related to feynman diagrams but also the relativistic scalar propagator term. First of all, this interaction: The cross represents a self-interaction via the mass and characterised by the term: -im^2, is this just some initial state...
  48. C

    Relativistic at freeze out? Definition of HDM

    Okay so in a HDM scenario, I have seen it described that the neutrinos were relativistic at freeze out. (If I could find it I would reference it.) Is this a contradictory statement? The condition for relativistic travel is E>>m but just before freezeout, the neutrino has energy equal to...
  49. N

    How is the Relativistic Larmor Formula Derived Using Dot Products?

    Hi all, Does someone know where to find the relativistic generalization of the larmor formula? I'm interested in the integral that involves a lot of dot products. So not the derivation that uses covariance to arrive at the formula. Are there any articles or books available that work out...
  50. J

    What relativistic effects to GPS receivers compensate for?

    So I understand the basics of the general and special relativistic effects on the speed of the satellite clocks onboard the GPS satellites, and why they are rigged to calculate time slower than an atomic clock at sea level. But then, in several articles, I read that GPS receivers are also...
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