Yes I know the difference between a "jet" and a rocket. I should have specified but I was trying to encompass everything thats propelled by a jet that doesnt need air that may not exactly fit in as a rocket. Rockets are propelled by a "jet" or stream of high speed high temperature gases along with gas turbines. Jet can encompass anything that accelerates using thrust really. But my bad on that because most people know a jet as a turbofan/turbofan/turboshaft/turboprop and you probably thought thats what I meant.
Anyway, with x amount of propellant, is exhaust velocity the main factor in determining peak velocity? Ie, as the vessel gets to a point where its travelling at the same speed and eventually faster than the exhaust velocity, wont it use more and more propellant for the same change in velocity the farther away the vehicles velocity gets from the exhaust velocity? Like the more it accelerates away from the exhaust velocity, the less efficient it is? Or does the rate of acceleration stay the same up until drag starts to take effect?
Also, whats the difference in exhaust velocity between: solid, liquid bipropellant, tripropellant, hybrid, etc?