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42 feet per gallon

nasa.gov

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Re: 42 feet per gallon

#31

Post by pmjordan »

wtallis wrote: post #20
jmillikin wrote: post #16

Earlier quoted context omitted.

It's only something you can visualise if you grew up with imperial units; "42 feet per gallon" is not inherently easier than "3.4 meters per liter", nor "125.7 gallons per mile" than "296 liters per km".

But all of those are far more accessible than 29573.53L/100km, which most people would just round up to "a hell of a lot". Using conventional units doesn't really help when the magnitude is so high.

30000 litres is the same as 30 cubic metres, i.e. "small swimming pool". Easy.

Re: 42 feet per gallon

#32

Post by photon_off »

spc476 wrote: post #11
drv wrote: post #10

Earlier quoted context omitted.

Seems to be about 3 miles from most of the launch pads to the VAB, so about 377 gallons for a one-way trip ( http://www-pao.ksc.nasa.gov/nasafact/count3teaf.htm ) The crawler can travel about 1 MPH loaded; the tour guide at KSC (at least when I was there several years ago) made a big deal about the blazing 2 MPH it can do when unloaded. :)

The closest observation point is three miles from the launch pads, so yes, the VAB (Vehicle Assembly Building; it's insanely large) is probably around three miles as well. Why the three mile distance? Back during the Apollo program, engineers determined that if the Saturn V were to explode on the launch pad, the resulting fireball would be around four or file miles in diameter. I think it's a similar radius for the S…

That sounds like an impossibly huge fireball for a rocket. IIRC even nukes don't create fireballs that large. Maybe I'm underestimating the amount of energy in a rocket.

My guess is that the main threat would be an off course rocket, or debris from an explosion, and that the probability of damage is acceptably low 3 miles away.

Re: 42 feet per gallon

#33

Post by cabalamat »

axod wrote: post #13
rue wrote: post #12

So, 12,8m/3,78541178l or EU standard combined: 29573,53l/100km? I wish at least sciency articles used SI.

The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.

> The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize.

Can you tell me quickly, without getting out pen and paper, how many gallons in 42 cubic feet? I suspect I can calculate how many litres in 42 cubic meters a damn sight quicker.

Re: 42 feet per gallon

#34

Post by cromulent »

axod wrote: post #13
rue wrote: post #12

So, 12,8m/3,78541178l or EU standard combined: 29573,53l/100km? I wish at least sciency articles used SI.

The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.

OK, so that's about 50 feet per gallon, using imperial gallons instead of US gallons (assuming they used dry gallons rather than wet ones).

Hmmm. Maybe it's better to say 1.5 chains to the peck to avoid confusion over the different gallons.

Re: 42 feet per gallon

#35

Post by jules »

axod wrote: post #13
rue wrote: post #12

So, 12,8m/3,78541178l or EU standard combined: 29573,53l/100km? I wish at least sciency articles used SI.

The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.

Well, he multiplied both numbers by a huge number and included far too many digits, obscuring what it means. Here comes the advantage of SI (notice that only multiplication by 10 is needed):

    29573.53l/100km = 0.29573531 l/m =~ 0.3 l/m
A way to visualize this is that if you put the fuel needed in a pipe along the route the vehicle rides, then the pipe has a cross section of 3 cm^2 (hey those SI units are handy!).

Re: 42 feet per gallon

#36

Post by axod »

demallien wrote: post #21
axod wrote: post #13

Earlier quoted context omitted.

The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.

Where by "humans" I assume you mean "Americans"? I've lived in three countries, none of which use gallons, and only one of which used miles...

I'm from the UK where we often use imperial.

Re: 42 feet per gallon

#37

Post by rue »

RK wrote: post #22
axod wrote: post #13

Earlier quoted context omitted.

The numbers you just put above mean nothing to me. Feet per Gallon is something humans can visualize. I'm sure I'll get downmodded to hell for expressing this opinion here, but I really do prefer imperial measurements.

It would have been more meaningful if rue had normalized it to 3.38 m/l. Those are human visualizable units.

Quite true, but I specifically wanted to get the standard combined "fuel efficiency" figure to compare against other vehicles easily. As has been demonstrated, it is quite simple to convert to simpler figures.

Re: 42 feet per gallon

#38

Post by [deleted] »

axod wrote: post #36
demallien wrote: post #21

Earlier quoted context omitted.

Where by "humans" I assume you mean "Americans"? I've lived in three countries, none of which use gallons, and only one of which used miles...

I'm from the UK where we often use imperial.

[deleted]
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