Fuel velocity vs exhaust velocity difference?

AI Thread Summary
Fuel velocity refers to the speed of the fuel relative to Earth, while exhaust velocity is the speed of the exhaust relative to the rocket itself. The relationship between these two is defined by the equation: fuel velocity equals rocket velocity minus exhaust velocity. Exhaust velocity remains constant due to the consistent power output of the rocket engine. Understanding this distinction is crucial for analyzing rocket performance and propulsion dynamics.
liddojoe
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hi all,

i've been confused about what the difference is between fuel velocity and exhaust velocity. apparently, fuel velocity is equal to rocket velocity minus exhaust velocity. attached are screenshots of the textbook reading that confused me. if anyone can explain this section to me, i would greatly appreciate it!

thanks!
joe
 

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hi joe! welcome to pf! :smile:
liddojoe said:
i've been confused about what the difference is between fuel velocity and exhaust velocity. apparently, fuel velocity is equal to rocket velocity minus exhaust velocity.

fuel velocity, vfuel, is the velocity of the fuel (relative to earth)

exhaust velocity, vex, is the velocity of the fuel relative to the rocket

vex is constant (because the rocket engine has constant power) :wink:
 

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