Thread: Acceleration in space.

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

2.

3. 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

4. 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.

5. this question is just silly

6. 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.

7. Which question was that an answer to Leo?

8. Originally Posted by Megabrain
Which question was that an answer to Leo?
good question
leo did you forsee the question?

9. Originally Posted by Megabrain
Which question was that an answer to Leo?
The initial one !?!?!

10. 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'.

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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

17. 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.
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.

18. 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.

19. 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:

20. 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.

21. Originally Posted by Guitarist
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.

22. 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:

23. 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

24. Damn the pair of you! almost a week without a mod edit! - and then they come along like friggin buses!

25. 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.

26. 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.

27. 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.

 Bookmarks
Bookmarks
 Posting Permissions
 You may not post new threads You may not post replies You may not post attachments You may not edit your posts   BB code is On Smilies are On [IMG] code is On [VIDEO] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are On Terms of Use Agreement