Throwing a ball in a moving train

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Discussion Overview

The discussion revolves around the behavior of a tennis ball thrown vertically in a moving train, exploring concepts of relative motion, air resistance, and kinetic energy. Participants consider different scenarios, including throwing the ball inside the train versus on top of the train in windy conditions.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants assert that when a ball is thrown straight up in a moving train, it will land back in the same spot due to the closed environment where the air is still.
  • Others question the outcome if the ball is thrown from the roof of the train, suggesting that wind may affect its trajectory.
  • One participant emphasizes that the ball, the person, and the air inside the train share the same velocity, which influences the ball's motion.
  • A participant introduces the idea that external wind acts as a force, potentially altering the ball's path when thrown outside the train.
  • Another participant challenges the need for a moving train to observe the effects of wind on a ball, proposing a thought experiment about the ball's motion in space and its kinetic energy.

Areas of Agreement / Disagreement

Participants express differing views on the effects of wind and the principles of relative motion, indicating that multiple competing perspectives remain without consensus.

Contextual Notes

Some assumptions about the effects of wind and the conditions under which the ball is thrown are not fully explored, leaving certain aspects of the discussion unresolved.

nobelium102
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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
right?
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?
 
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nobelium102 said:
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
right?
Does this happen because i am in a closed space where the air is still?
Right!
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?
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.
 
Remember that it's not just the train traveling 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.
 
wind => external force
 
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 which 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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