membership ?

[Brad WalkerParticipant]

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 PlattnerParticipant]

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 PlattnerParticipant]

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?

[Author]

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