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Subject: 
Re: Falling thru earth revisited
Newsgroups: 
lugnet.off-topic.geek
Date: 
Wed, 22 Jun 2005 16:20:57 GMT
Viewed: 
2344 times
  
In lugnet.off-topic.geek, David Eaton wrote:
In lugnet.off-topic.geek, David Koudys wrote:
My idea is that basically the accelleration of an object going towards the
center due to gravity and the decelleration of an object from the center to
the other side basically cancels out, so we would just have to measure the
distance/time from the entry point to the exit and figure in the thrust of
the rocket across that distance and we'd have a pretty good idea of how
fast it'll be going.

One other thing to think about is the amount of time something's been
exposed to something that increases its speed. For example:

Uncle Ben and Aunt Jemima have a race from point A to point B, and
back to point A. Aunt Jemima stays at a constant speed throughout
the race. Uncle Ben starts the race at *double* Aunt Jemima's speed,
up until he reaches point B, at which point he travels back to point
A at *half* her speed.

At first thought, you'd think that they'd tie at the finish line,
but really, Jemima finishes in 4/5 of the time that Ben finishes.
(He'd need to go 2/3 as fast on the return loop in order to tie).
Essentially, since he's going slower for longer, it slows him down
more than you might intuitively expect.

Not sure how that would affect the rocket model.

Yeah, like do you have to fly at an angle to avoid hitting the sides
due to the earth's rotation?

Hmm. Now I'm curious as to whether there's any merit to that idea or not.

Isn't this the whole idea behind the gravity slingshot they use
to accelerate spacecraft?  It worked in "2010" and I think NASA uses
it all the time on space probes.



Message is in Reply To:
  Re: Falling thru earth revisited
 
(...) One other thing to think about is the amount of time something's been exposed to something that increases its speed. For example: Uncle Ben and Aunt Jemima have a race from point A to point B, and back to point A. Aunt Jemima stays at a (...) (19 years ago, 8-Jun-05, to lugnet.off-topic.geek)

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