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B Why do astronauts float in space?

  1. Mar 25, 2016 #1
    Another question XP.
    I have read several articles about the reason why astronauts float in space. I understand that this is because astronauts and the spaceship undergo free falling due to gravitational pull by the Earth. However, this doesnt explain why astronants float inside the spaceship.
  2. jcsd
  3. Mar 25, 2016 #2


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    If the astronauts and the spaceship are moving at the same velocity and are being accelerated identically, they should stay in the same position relative to each other, yes? Why would you expect this to change just because the astronaut is inside instead of outside?

    Are you, perhaps, thinking that the space ship somehow shields the astronauts from the gravitational pull of the Earth? It does not.
  4. Mar 25, 2016 #3
    Then if the astronauts initially stand on the ground of the spaceship, will the astronauts float ?
  5. Mar 25, 2016 #4


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    Ideally, if he or she is initially standing, just touching the spacecraft floor but exerting no force then the astronaut would stay right there.

    Practically, if they push off even a teeny bit or if there is any air circulation they can gently float away.
  6. Mar 25, 2016 #5
    Thank you very much,
    I understand now :D
  7. Apr 3, 2016 #6


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    Gravity is very weak. It takes the mass of the whole planet to produce the force you feel when standing on the earth. A spacecraft has much less mass than a planet so you can't feel anything attracting you to the spacecraft but there is a very very small force.
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