Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Relativistic Rocket: Finding the change in velocities in different reference frames

  1. Feb 9, 2012 #1
    1. The problem statement, all variables and given/known data
    I a little lost on how to use the relativistic velocity addition formula to determine the increase in speed "v" over a short time interval in the Earths frame of reference, for a rocket having left earth at rest and traveling through space accelerating at constant acc. of 9.81 m/s^2. In the rockets instantaneous frame of reference, the increase in speed is (9.81m/s^2)*Δt where Δt is the proper time interval. The equation must be modified to determine a speed increase Δv over a short interval of time from the Earth frame of reference. I guess the question I have is if I can use this formula to solve for the change in velocity over a small interval of time, for a different reference frame?

    2. Relevant equations

    v=u+v'/ sqrt(1+v'u/c^2)

    3. The attempt at a solution
    Here's what I have so far, not sure if its close:

    Last edited by a moderator: Feb 9, 2012
  2. jcsd
  3. Feb 9, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Education Advisor

    Re: Relativistic Rocket: Finding the change in velocities in different reference fram

    You should review the velocity-addition formula. Identify what v, u, and v' stand for as it relates to this particular problem, and then try again.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook