[Ol' Dan Tucker]

im just asking... that makes sense in atmosphere, but in space how does a total vacuum determine/receive exhaust pressure/speed?? how does a total vacuum determine if that craft is doing 3 mph or 30,000 mph??

Newton's Second Law: For every action, there is an equal and opposite reaction.

Blow exhaust out a rocket nozzle at 30,000 MPH (theoretical) and the spacecraft will be propelled to 30,000 MPH, but no more than that.

The only way a spacecraft can go faster is by using the gravity of a planet to slingshot it to higher velocities, which is what NASA uses for exploration of the outer solar system.

[Ol' Dan Tucker]

Oops. That’s Newton’s Third Law, not his Second.

[sit-rep]

btt!!

[Neverlift]

“Newton’s Second Law: For every action, there is an equal and opposite reaction.

Blow exhaust out a rocket nozzle at 30,000 MPH (theoretical) and the spacecraft will be propelled to 30,000 MPH, but no more than that.”

PLEASE go back and take your high school physics class again.

That would be NEWTON”S THIRD LAW and it is about FORCE not SPEED.