Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Moving In space

  1. Mar 10, 2015 #1
    Can a person suspended in space with nothing to push off of, turn themselves around?
     
  2. jcsd
  3. Mar 10, 2015 #2
    I think he can't if the space is empty and the weight is absent.
    He can only produce internal forces which let him to extend the arms and to rotate the breast for example..
    Every movement he makes can't accelerate him because it creates equal and opposite reaction forces
     
  4. Mar 10, 2015 #3

    A.T.

    User Avatar
    Science Advisor
    Gold Member

     
  5. Mar 10, 2015 #4
    Yes, it's true: a cat rotates because it can produce two equal and opposite angular momentums, so the net angular momentum is zero.
     
  6. Mar 10, 2015 #5

    A.T.

    User Avatar
    Science Advisor
    Gold Member

  7. Mar 10, 2015 #6

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

  8. Mar 10, 2015 #7

    DaveC426913

    User Avatar
    Gold Member

    Yes. If he gyrates his arms/legs in a clockwise direction, his torso will turn counterclockwise. Once he stops moving his limbs, he will be facing a new direction and no longer rotating.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook