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Throwing a ball in a moving train

  1. Jul 30, 2011 #1
    If you throw a tennis ball straight up in a moving train, the ball will drop back down on the same spot so you can catch it
    Does this happen because i am in a closed space where the air is still?
    What would happen if i went on top of the train (so i guess the roof of the train) and did the same experiment?
    will the ball be flown backward because of the wind?
  2. jcsd
  3. Jul 30, 2011 #2


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    You need not to risk that much. Just take your tennis ball and go to backyard of your house during stormy wind to see what happens.
  4. Jul 30, 2011 #3


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    Staff Emeritus
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    Remember that it's not just the train travelling at 80mph! You, the ball and the air in the carriage all have the same velocity. The wind outside the train is the same wind resistance that a ball would feel if you fired it from standing to 80mph.
  5. Aug 4, 2011 #4
    wind => external force
  6. Aug 4, 2011 #5
    you don't need a moving train to see if a ball moves with wind!
    Actualy the question would be why didn the ball remain in its place in space when you threw it in the air and didn go bakward? in fact, you re stick to the train but it's not? why didn it loose the train speed when not being attached to it? well that's cz it's got some kinetik energie wich let it move with nearly same speed! and that's why(ignoring wind) u'll get the same results at the top of the train
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