Re: Internal Rocket Effect

In article <IKadnVj2SceAVAbVnZ2dnUVZ_q_inZ2d@xxxxxxxxxxx>, Spaceman says...



p[snip]


Actually, the flow will pressurize the entire low-pressure
side of the tubing. That implies that the molecules
are hitting the sides.

Correct and it not only hits the sides,
it collides with stuff that hits the sides and some of that
stuff is diverted forward also.

But as he already pointed out, it carries kinetic energy with it, but the total
momentum of the "stuff that hits the sides" is ZERO. So that does not help you.

So not all of it will hit the "back" wall.

True. But as already explained SO many times, that does not help you.


The flow will also hit the back.

Yes, but not all of it.
It could not all do such since air is not a solid
and solids do not behave like that.
they will compress against each other
and cause multiple directions of reflection
including some forward off the one hitting the sideset

Yet again: this will happen, but it does not balance the momentum. You are using
this irrelevant motion as an excuse to ignore the fact that you have not
accounted for the momentum transfer to the wall opposite the jet (whence the gas
started).




Um...pool tables require gravity to operate. Did you want to
instead use a ball suspended in a box with some sort of
solenoid-actuated "cue stick", floating in free space?

Why do you pull that stupid ***.

Because despite your protests, it is not "stupid ***".

Of course pool table do.
I said remove the friction and that actually lis like removing the
damn "table part itself and leaving only the bumpers and
the compressable balls I mentioned instead of actual pool balls.

You miss the point. You just admitted that "of coruse pool table[sic] do", when
he just said "require GRAVITY". But removing friction has NOTHING to do with
gravity.

Unless, of course, you meant removing the friction between the pool table's legs
and the floor. But this is not what you said.

However, just in case that is what you really meant, what would happen in that
case is that when the one ball hits the 1000 balls (of your earlier statement),
then the whole pool table will recoil, cancelling out the gain of momentum that
had been realized by shooting the 1 ball towards the 1000.

[snip]

Correct, and the amount of balls that hit those thousand
will not send all the force to the back wall only.

You are confusing 'force' and 'momentum'. All the momentum will be transmitted
to the back wall only. There is no other way to get the vector sum of all
momenta before the collision to match that after.

This is the consequence of Newton's Third Law which you keep ignoring.

.

Quantcast