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Relativity problem

  1. Mar 30, 2010 #1
    You are in a space craft that is traveling at 0.9c (according to the passenger), and you want to get to a planet that is 11 light years away. How long will it take to get to the planet ?

    This may seem like a simple problem but it's been bugging me. I answered this question by using the simple time = distance / speed since the person is in the same frame of reference as the space craft, is this correct?
     
    Last edited: Mar 30, 2010
  2. jcsd
  3. Mar 30, 2010 #2

    tiny-tim

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    Hi doc.madani! :smile:
    The question isn't clear …

    according to the passenger, the speed of the space craft is zero. :confused:

    I'll guess it means, if the speed and distance as measured by a stationary observer are 09.c and 11 l-y, then how long on the passenger's clock does it take?
     
  4. Mar 30, 2010 #3
    I was just quoting the exact question that I was given In a test :s however since the passenger is in the same frame of reference (inertial frame if reference) to the space craft you can simply use the time = distance over speed formula ?
     
    Last edited: Mar 30, 2010
  5. Mar 30, 2010 #4

    tiny-tim

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    Yes, but if he got the 11 light-years from a standard Galactic Maritime Federation astro-chart (sorry, I don't have a link :redface:), that'll be the distance in a stationary frame, and you need the distance in his frame. :wink:
     
  6. Mar 30, 2010 #5
    Ok for arguments sake let's say it was 11 light years in his frame of reference :) your starting to scare me that there's more to the question than I anticipated :s lol that's ok
     
  7. Mar 30, 2010 #6

    tiny-tim

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    If it was 11 light years in his frame of reference, then yes, he can divide by the speed to get the time on his clock. :smile:
     
  8. Mar 30, 2010 #7
    ohh :) good thank you very much tiny-tim for your help :D
     
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