1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Travelling to Mars at constant velocity? Weightless?

  1. Sep 12, 2015 #1
    If I'm travelling on a spaceship at a constant velocity (say 10000 m/s) towards Mars will I feel weightless, or will I feel nearly weightless because I will still be slightly affected by gravity?

    I know that when astronauts are in the ISS they feel weightless because they are in a constant state of free-fall, but I don't feel like the same idea applies to the spaceship travelling to Mars. Any clarification would be great! Thanks!
     
  2. jcsd
  3. Sep 12, 2015 #2

    DaveC426913

    User Avatar
    Gold Member

    Why wouldn't it apply? They're still in orbit.
     
  4. Sep 12, 2015 #3
    How are they still considered to be in orbit if they are travelling to another planet, not around? Can we consider anything travelling through space to be in an orbit of some type?
     
  5. Sep 12, 2015 #4

    DaveC426913

    User Avatar
    Gold Member

    Not anything, just anything near the sun that is not under power.
     
  6. Sep 12, 2015 #5
    Ok that makes sense! Thanks!
     
  7. Sep 12, 2015 #6

    DaveC426913

    User Avatar
    Gold Member

    Although, it' not the 'in orbit' that makes them weightless, it's the 'not under power'.

    If they were floating one jillion miles away in interstellar space, they'd effectively be stopped in space, not exactly in orbit, but they'd still be weightless.
     
  8. Sep 12, 2015 #7

    russ_watters

    User Avatar

    Staff: Mentor

    I would generalize to say that any time you are not under power in space you are in free fall toward "something", it's just that "something" may not always be readily apparent.
     
  9. Sep 12, 2015 #8
    During a trip to Mars the velocity wouldn't be constant in free fall.
     
  10. Sep 12, 2015 #9

    russ_watters

    User Avatar

    Staff: Mentor

    True! Dave added the important qualifier, that "not under power" is the key state of affairs during a normal trip. Hopefully the OP now recognizes that "constant velocity" is an unusual condition to apply. I suspect he mistakenly believed that when coasting during a normal trip, velocity would be constant.
     
  11. Sep 12, 2015 #10
    I will be deviding you're question into 2, if you don't mind.

    If you have constant velocity Then the added forced to you will be zero, even if gavity affects you, constant velocity means something is negating this gravity.
    That means weightless (not massless). On the other hand you might feel presured by the forces.

    On the other hand, In space, espacially on a trip to a different planet and in a solar system like ours, it is unlikely that if you feel significent force there will be something to negate it in space. So in a free fall to a planet you will change velocity, meaning acceleration . And that means force like F=ma using angular acceleration.

    Hope I helped and not mislead, even though members here have deeper understanding of this subject.
     
  12. Sep 13, 2015 #11

    russ_watters

    User Avatar

    Staff: Mentor

    How can you feel "pressured", but weightless? I'm not even sure what "pressured" means. Sorry, but maintaining constant velocity while under the influence of gravity requires applying a force opposite the gravitational force. A force you feel.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Travelling to Mars at constant velocity? Weightless?
Loading...