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Homework Help: Special relativity noob problem 2, Dopler shift.

  1. Nov 16, 2008 #1
    1. The problem statement, all variables and given/known data

    By 2025 a spaceship shuttle service operates between the Earth and Mars. Each
    spaceship is equipped with identical mono chromatic head and tail lights, and their cruising speed v relative to earth, is such that the headlight of a homeward-bound spaceship appears green ( lambda = 500 nm) and the tail-light of a departing spaceship appears red(lambda = 600 nm).(i) What is v/c ?(ii) What is the wavelength of the headlight of an earth-b ound spaceship is observed froman outward b ound one?

    2. Relevant equations

    http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/reldop2.html" [Broken]

    3. The attempt at a solution
    I have no idea where to start.
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Nov 17, 2008 #2


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    Science Advisor
    Homework Helper

    Hi -Vitaly-! :smile:

    The two lights are the same colour, but they look different because of the Doppler shift.

    Just plug in the equations, and see what happens! :smile:
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