[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*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*Subject*: Re: Wait a moment*From*: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)*Date*: Sat, 30 Mar 1996 17:51:29 +0100

To Kevin, >Too late, I already did. :) oh well, just ignore my comments It happened to me several times, but I think some of you comments are still valid, so I will answer them here. The minima are: Vstart Vexh optimal Fuel:ship-ratio Energy per kg of ship (in Joules) 0.1 0.062 5.36 7.45E14 0.2 0.121 5.84 3.25E15 0.3 0.180 6.40 8.11E15 0.4 0.240 7.06 1.64E16 0.5 0.300 7.87 2.97E16 0.6 0.364 8.91 5.23E16 0.7 0.433 10.38 9.21E16 0.8 0.512 12.72 1.73E17 0.9 0.615 17.75 4.04E17 0.99 0.803 52.00 3.12E18 0.9996 0.906 238.81 2.91E19 Vstart is indeed the velocity that the starship has just before it starts decelerating. Energy per kg of ship is the total amount of energy needed, to calculate the mean power, you could devide the Energy by T, the time it takes to decelerate the ship. Here are a few of these power numbers, Vstart P[0] P[T] 0.1 5.01E08 9.35E07 0.5 4.19E09 5.34E08 0.9 2.73E10 1.54E09 0.99 1.55E11 2.98E09 0.9996 1.23E12 5.14E09 P[0] is the power needed at the beginning of the deceleration, P[T] is the power needed at the end of the deceleration. The difference between P[0] and P[T] is caused only by the decrease of the total mass of the ship. Oh yes, the power and energy mentioned here are all relative to the starship, not to Earth. This means that the doppler shift increases all numbers when one takes Earth as reference point. (which is important because it has to generate the power) The influence of the doppler shift is shown here: Vstart Energy per kg of ship (in Joules) 0.1 7.45E14 7.73E14 0.2 3.25E15 3.50E15 0.3 8.11E15 9.08E15 0.4 1.64E16 1.91E16 0.5 2.99E16 3.64E16 0.6 5.23E16 6.69E16 0.7 9.21E16 1.25E17 0.8 1.73E17 2.53E17 0.9 4.04E17 6.62E17 0.99 3.12E18 7.02E17 0.9996 2.91E19 9.26E19 The first row is the ENERGY relative to the starship, the second row is the energy relative to Earth. I won't show the power numbers here, but I think you can make a rough guess. The influence of the doppler shift is calculated as follows: 2 Sqrt[1 - b ] f'= f --------------- where b=v/c 1 - b v[t]=c Tanh[a t/c] U = h*f so just linear dependence T 2 / Sqrt[1 - b ] E = | P[t] --------------- dt where b = v[t]/c / 1 - b 0 Timothy P.S. If someone likes a complete document (instead of the fractured ones) just sent me a mail.

- Prev by Date:
**OK, here the right calculus (I hope)** - Next by Date:
**Black horse** - Prev by thread:
**Re: Wait a moment** - Next by thread:
**OK, here the right calculus (I hope)** - Index(es):