David Roberson
<http://www.mail-archive.com/[email protected]&q=from:%22David+Roberson%22>
Sat, 08 Feb 2014 17:47:05 -0800
<http://www.mail-archive.com/[email protected]&q=date:20140208>
"There should not be any extra energy than was present in the high velocity gas
and other cloud before the impact. The energy after the collision is
distributed differently since the large volume of gas would likely be heated by
the collision. Any additional heat energy that is passed to the large volume
of gas is extracted from the high velocity stream. Of course there may be
other places that energy can be deposited after the collision, but the total
before and after should be the same. Consider that the high velocity incoming
gas has a significant quantity of kinetic energy due to its motion. Once it
has collided, it slows down as it becomes a portion of the larger gas cloud.
That is the source of the extra energy you are seeking."
To restate my problem. How can the momentum of the large volume of gas
be the same as that of the high velocity jet, that is conservation of
momentum, while the gas gets hotter? The energy from the heat must come
from the momentum of the high speed gas.
My suspicion is that with a large volume of gas it would end up with
very little momentum, most of the energy would end up as heat. I know
that is not the standard answer as this would make it possible to get
thrust from a closed system. I suppose my question is /why/ this
doesn't happen.
