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Re: Physics help (I found it!)
- To: KellySt@aol.com, kgstar@most.fw.hac.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, lparker@destin.gulfnet.com, DotarSojat@aol.com, neill@foda.math.usu.edu, 101765.2200@compuserve.com, MLEN3097@Mercury.GC.PeachNet.EDU
- Subject: Re: Physics help (I found it!)
- From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
- Date: Sat, 18 May 1996 00:01:12 +0100
Kelly wrote:
>>Well thats part of it. It certainly doesn't give me a warm comfident
>>feeling when our numbers are that far apart! Eiather we're talking about
>>something fundamentally different and don't realize it, one of us has a
>>blown calculator, or one of us is badly misappling some equation.
Was that you?
>We were both talking about something fundamentally differnt, but didn't
>know it! The difference was all due to the slightly different Delta V.
>The Exponential makes a hellish difference given even slight differnces in
>the speed assumptions.
>
>(See why I always want to see examples with numbers and units with your
>equations Tim?)
The numbers where there before, but apparently they did not help much.
>So a 55 to 1 fuel ratio with a Vexh of 2E7 m/s:
>
>55 = exp (?/2E7)
>
>or
>
>2e7 * Ln (55) = 80E6 = .267c
>
>So we can still get a burn down from over 1/4th c with the same fuel ratio.
>Giving a touch under 17 years for a flight time to Alpha C. Much better
>than I was afraid of.
That mass ratio is only for acceleration OR deceleration, if you want to do
both you need to square that mass ratio. (55^2=3025)
Isn't AC a bit too close?
Timothy