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Thread: Acceleration in space.

  1. #1 Acceleration in space. 
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    8) If a body is pushed with a force in space where there is no opposing force then will the body be accelerating forever?


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  3. #2  
    Forum Ph.D. Nevyn's Avatar
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    no, for acceleration you need a constant force wich is applying more and more force, if you give something a nudge in space it will travel forever ( or at least untill it crashes into something


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  4. #3  
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    It's velocity should remain the same as at the moment the force was removed. If you are next going to say ah but the acceleration of the galaxies, forget it.
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    this question is just silly
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

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    Forum Professor leohopkins's Avatar
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    As a body moves through space at increasing speeds, its mass also increases therefore you will need more and more energy. i.e a constant and bigger force to get the object to accelerate.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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    Which question was that an answer to Leo?
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    Forum Isotope Zelos's Avatar
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    Quote Originally Posted by Megabrain
    Which question was that an answer to Leo?
    good question
    leo did you forsee the question?
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

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  9. #8  
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    Quote Originally Posted by Megabrain
    Which question was that an answer to Leo?
    The initial one !?!?!
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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  10. #9  
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    Well as every other poster noted the original question does not say 'continuously pushed' or 'pushed with a constant force' so we take it he means just 'pushed'.
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    well i got up to one question by seeing these posts that if a body is left near the earth(outside earth's atmosphere) in space with some velocity will it go in the same direction or orbit around earth due to gravitational force.
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  12. #11  
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    That depends on how much velocity, how far above the earth's surface you left it and, the direction of the velocity. If you just left it 'stationary' WRT the earth then it would bgin to fall. If you gave it velocity it would fall in an arc, if that velocity were sufficient it would orbit or even at greater velocities 'arc' past the earth.
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    Forum Senior anand_kapadia's Avatar
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    I didn't understand what you said as arc will that body return back to earth.
    Please describe the condition in which the body would revolve around the earth.
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  14. #13  
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    If you place an object above the earths atmosphere and give it sufficient velocity it will orbit the earth. To give an exact example requires several pages of newtonian, Keplarian physics.

    As an example though the velocity needed to orbit the earth at an altitude of 200 miles is about 17500 miles per hour, giving a 91 minute orbital period. At 22,000 miles the velocity would be 3250 miles per hour and at 240,000 miles (ie the moon) the velocity is around 1000 miles per hour.
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    Quote Originally Posted by Megabrain
    Well as every other poster noted the original question does not say 'continuously pushed' or 'pushed with a constant force' so we take it he means just 'pushed'.
    Of course I understand that. I was explaining the only method how a body will accelerate continualy in space.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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    Quote Originally Posted by Megabrain
    If you place an object above the earths atmosphere and give it sufficient velocity it will orbit the earth. To give an exact example requires several pages of newtonian, Keplarian physics.

    As an example though the velocity needed to orbit the earth at an altitude of 200 miles is about 17500 miles per hour, giving a 91 minute orbital period. At 22,000 miles the velocity would be 3250 miles per hour and at 240,000 miles (ie the moon) the velocity is around 1000 miles per hour.
    Mega, dont swear like that. Its extremly rude in science using those words
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

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  17. #16  
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    Quote Originally Posted by Megabrain
    That depends on how much velocity, how far above the earth's surface you left it and, the direction of the velocity. If you just left it 'stationary' WRT the earth then it would begin to fall.
    Except at a Lagrange point, so I'm told.
    Quote Originally Posted by leohopkins
    As a body moves through space at increasing speeds, its mass also increases
    Not according to my physics buddies - mass is a Lorentz invariant, as are all scalars.

    But of course, I'm way out of by league here.
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    Gravity extends to the edge of the universe, since it travels at light speed, even there [theoretically] there will be some 'pull' from the earth.
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  19. #18  
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    Quote Originally Posted by Guitarist
    Not according to my physics buddies - mass is a Lorentz invariant, as are all scalars.

    But of course, I'm way out of by league here.
    Evidently so. :wink:
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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  20. #19  
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    Quote Originally Posted by leohopkins

    Evidently so.
    Right, I welcome you as my mathematical physics tutor.

    So, tutor. What is a Lorentz transformation on a real space? Or on a complex space? What, in fact does "space" mean in this context?

    Please help, as you see I'm a bit behind you.
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  21. #20  
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    Quote Originally Posted by Guitarist
    Quote Originally Posted by leohopkins

    Evidently so.
    Right, I welcome you as my mathematical physics tutor.

    So, tutor. What is a Lorentz transformation on a real space? Or on a complex space? What, in fact does "space" mean in this context?

    Please help, as you see I'm a bit behind you.
    MOD EDIT: Text removed, if you must copy and paste you are obliged to credit the source.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

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  22. #21  
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    Quote Originally Posted by Guitarist
    Except at a Lagrange point, so I'm told.
    If you leave a satellite in a lagrange point it will not be stationary above the earth, the earth moon lagrange or any of the 5 earth sun moon points are not stationary. :wink:
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  23. #22  
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    Hi leohopkins!

    deleted But you are pretending to know things that you don't, so we can't. I have no idea where you got your last post from, but it sure wasn't from your head (be honest, now!).

    Deleted
    I have no doubt that this post will be "politically corrected" (i.e. deleted) so let me quickly advise you not to quote things you can't defend
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  24. #23  
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    Damn the pair of you! almost a week without a mod edit! - and then they come along like friggin buses!
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  25. #24  
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    Yeah Megabrain, I was well out of order, sorry.

    Also leohopkins, although I stand by the substance of my post, I expressed myself very aggressively (if you glimpsed it), so sorry to you too.
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  26. #25  
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    Quote Originally Posted by Guitarist
    Yeah Megabrain, I was well out of order, sorry.

    Also leohopkins, although I stand by the substance of my post, I expressed myself very aggressively (if you glimpsed it), so sorry to you too.
    That is okay. Apology accepted. No - It wasnt from my head, I copied and pasted (that which was deleted) from a website as you seemed interested in the Lorenz transformation; which incidentaly I had never heard about and having read about it still have absolutely no idea what it means. I have heard of the "Lorenz Contraction" though. I should have made the effort to find out who it was written by but the writer did not leave his/her name underneath the text so had no idea. I should have posted the link instead really but as it was a short essay I thought copy and paste easy for everyone.
    The hand of time rested on the half-hour mark, and all along that old front line of the English there came a whistling and a crying. The men of the first wave climbed up the parapets, in tumult, darkness, and the presence of death, and having done with all pleasant things, advanced across No Man's Land to begin the Battle of the Somme. - Poet John Masefield.

    www.leohopkins.com
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  27. #26  
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    As a matter of note, you may copy and paste but a short paragraph or your own summary is the rule of this forum, it must also be credited, if as in this case (where I found it on another forum un-credited) then a link is ok with a summary but not a cut and paste, copyright is the issue here.

    THanx.
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