ORIGINAL: causeitflies
Remember, a jet is not a reaction motor such as a rocket; it has to push against something to function, (air) if that air is moving at the same speed as its efflux velocity then there is no effective thrust!
Paul
I think you better re-think that statement. Our jets ARE reaction engines. The difference is that the jet gets O2 from the air and the rocket carries its own.
Exactly correct. Turbojets are reaction motors and the total thrust is a function of the combination of its exhaust area and exhaust velocity.