Originally Posted By: paul
What this means is that your tube-based system experiences a force, and thus gains momentum, from that initial acceleration of the air from rest to the speed of sound - a force determined by [Pt-Pe]Ae. However, the force generated by mass flow - and thus that momentum - is countered by an equal but opposite "choking" force. Ergo m(dot)Ve is zero with a tube.

still the mass will come out of the tank given its tube is
58 inch diameter.

and when the mass comes out , and it will come out , the momentum will be mass x velocity.


I dont care how you word it , the pipe will move.

because the mass moves inside.

Now you're mixing issues.

The air that leaves the nozzle/tube will have momentum - a momentum given to it by the force [Pt-Pe]Ae.

However, the momentum of the air leaving the nozzle/tube will impart no net momentum on your pipe, for the simple reason it'll transfer that exact same amount of momentum in the opposite direction once it strikes the end of the pipe.

Equal and opposite momentums = your pipe does not move.