- This topic has 11 replies, 9 voices, and was last updated 15 years, 6 months ago by
Warren B. Musselman.
Warren B. Musselman.-
Posts
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Brad Walker
One more thing about membership. If I join NCR, is the membership based on a calendar year or does it run for a complete year from time of signing up.
Thanks.
Ken Plattner
It runs for a complete year from when you join.
Ken
SCOTT EVANS
Hey…. WHats that formula up there?
Am I supose to know that? 😕Cineroc
Hey…. WHats that formula up there?
Am I supose to know that?only if you want to claim you’re a rocket scientist…
Roger
Mitch Smith
Unless my brain isn’t working correctly tonight…. The formula is for the acceleration of a rocket taking into account the rate at which the fuel is consumed along with the effects of atmospheric presure. Let us know how far I am off Ken.
Chris LaPanse
I don’t see an atmospheric pressure term. It’s just a basic form of the rocket equation.
(For that matter, it doesn’t even appear to have a gravity or drag term)
Ken Plattner
Right on, Chris. It’s the Ideal Rocket Equation – derived from the conservation of momentum of the rocket and fuel by Russian scientist Konstantin Tsiolkovsky in 1903 or so.
Simplistically, P=mV, so you can say that mv of the rocket = mv of the fuel. For the rocket, m is essentially constant, but the velocity changes. For the propellant, the mass changes, but the exhause velocity of the burning fuel is constant.
So,
m delta V = V delta m
mdv = vdm
Do the integration, etc…
SCOTT EVANS
Right on, Chris. It’s the Ideal Rocket Equation – derived from the conservation of momentum of the rocket and fuel by Russian scientist Konstantin Tsiolkovsky in 1903 or so.
Simplistically, P=mV, so you can say that mv of the rocket = mv of the fuel. For the rocket, m is essentially constant, but the velocity changes. For the propellant, the mass changes, but the exhause velocity of the burning fuel is constant.
So,
m delta V = V delta m
mdv = vdm
Do the integration, etc…
duh……….Hey Joe, what size motor should I put in this one? ……just give me the biggest one that will fit! 😉
Bruce R. Schaefer
Scott E, don’t question a guy with a degree in advanced mathematics. 🙄 He will differentially equate your derivative in no time flat, not to mention integrate your limits!
Ed Dawson
Thanks Scott. I have not laughed so hard in a while.
Hey Joe, what size motor should I put in this one? ……just give me the biggest one that will fit!
That’s what it all about, eh?
Brad Walker
Ken Plattner
SCOTT EVANS
Cineroc
Mitch Smith
Chris LaPanse
Bruce R. Schaefer
Ed Dawson
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