Originally Posted By: paul
the only reason that the pipe could move is the momentum of the mass moving inside the pipe.

Exactly - and [Pt-Pa]Ae calculate the portion of that derived from the differential pressure.

Originally Posted By: paul
if it moves slowly , unconstricted then not much force is produced.
if it moves faster by constriction , then much more force is produced.

Im right and your wrong , your just too boneheaded to admit it.

No, you're just too stupid to understand what that formula is calculating. There are two sources of force that move the pipe - the pressure differential and the expansion of the gas once it leaves the pipe (captured by the nozzle).

To calculate the former you need only the differential pressure and cross-sectional area connecting the two regions.

To calculate the later you need the mass and the acceleration provided by the nozzle.

Originally Posted By: paul
Its funny though, you lecturing me on math, when you seem to have completely missed the fact that you "corrected" my math by providing the same formula and changing one letter.

LOL, stupid is funny!

no I didnt I included the correct formula

In that case you can certainly show where your formula varieties from mine.

Of course, we both know you won't, as your formula is the exact same one I have been using since day 1. Swapping symbols doesn't change the formula itself.