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Thought Experiment on ToR postulate-1

  1. Oct 5, 2007 #1
    'All laws of physics hold good in all inertial frames of reference.'

    observer A - standing still on earth
    observer B - in jetplane-1 flying at mach-2

    jetplane-2 is moving at mach-1 co-directional to jetplane-1.

    A observes in accordance with Newton's 3rd law.

    B observes, fuel level going down in jet-2, exhaust moving out from the tail. But jetplane-1 is moving backwards for him, which is not in accordance with 3rd law.

    Again I know I am missing something here. Any clue what it is?

  2. jcsd
  3. Oct 5, 2007 #2


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    Staff: Mentor

    B observes that jetplane-2 is being blown backwards by the air which is rushing past him (B) at mach-2. Jetplane-2 is burning fuel in a half-successful attempt to make forward progress against this tremendous headwind.
  4. Oct 5, 2007 #3
    I'm sorry. this sort of an invalid answer. We can experiment this in vacuum as well.
  5. Oct 5, 2007 #4
    If you did this in vacuum, both "planes," if actively burning fuel, would be accelerating, making them non-inertial frames, in which observers will necessarily observe some sort of fictitious forces.
  6. Oct 8, 2007 #5
    that answers me. Wrong assumption. Thank you.
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