Land Speed Record Broken: 0-6,400 in Six Seconds 362
linuxwrangler writes "Researchers at Holloman AFB have broken their own two decades old land speed record for rail vehicles. The rocket powered sled covered the 3 mile track in roughly 6 seconds. Preliminary numbers put the sled's speed at mach 8.6 or about 6,400 mph - it covered the last 1.8 miles in just 1.3 seconds. The previous record of 6,122 mph was set on Oct. 5, 1982. Other accounts are at the Alamogordo Daily News, the Denver Post, and CNN."
Metric Conversion (Score:5, Informative)
"Researchers at Holloman AFB have broken their own two decades old land speed record for rail vehicles. The rocket powered sled covered the 4.8 km track in roughly 6 seconds. Preliminary numbers put the sled's speed at mach 8.6 or about 10300 km/h - it covered the last 2.9 km in just 1.3 seconds. The previous record of 9851 km/h was set on Oct. 5, 1982. Other accounts are at the Alamogordo Daily News, the Denver Post, and CNN."
Maybe we should make a rule that say you always have to supply metric and imperial units... It would make my job so much easier...
Re:Darwin award winner did it first? (Score:5, Informative)
Re:Darwin award winner did it first? (Score:5, Informative)
Re:Aww. (Score:2, Informative)
Re:Driver not Available for Comment (Score:5, Informative)
As another perspective, Top Fuel drivers in the NHRA cover a quarter of a mile in roughly 4.4 seconds, from a standing start, reaching speeds of over 320MPH. The 0-100 times are generally in the
Land speed record primer (Score:4, Informative)
Re:Well Rounded Education (Score:1, Informative)
improved grammer and spelling skills that are lacking in the technical."
OK, nice idea but it loses credibility when his/her post includes gems like this, "...humilaite them whenever possible." Or, "...astrology, the most rediculious of the sciences!" Or, "Whilst you want to trun collage into a trade school with yore narrow minded views that collage..." Or finally, "I'm going on to so a PhD in socialolgy..."
Come back when your improved spelling and grammar skills help you spell your major correctly and we'll talk. Until then, back to class, troll!
Re:Landspeed records don't impress me (Score:3, Informative)
Re:Metric Conversion (Score:2, Informative)
And still you think that the rest of us should do it in our heads? Quoting you:
Yes, because people can't do simple conversions in their head.
There are three (3) countries in the world that still uses the imperial system: Liberia, Burma and the US. Every other contry implements the metric system.. Look here [colostate.edu] if you're interested.
There's a certain "American Tunnel Vision Syndrome" around Slashdot, it seems..
Re:One problem (Score:2, Informative)
Having said that, they both stink because of the existence of the other. The simple fact that I have to wonder what "02/03/05" refers to because of the competing standards renders them all flawed. The only standard that anyone should use is the ISO 8601, which is as you mention yyyy-mm-dd (it's hardly a "Japanese" system - It's been used and advocated as a "metric" sort of date for many decades).
Re:The numbers don't add up! (Score:2, Informative)
Note - I am not writing out all the digits, but I kept them when doing the math to avoid rounding error.
Given:
x = x0 + v0*t + 1/2*a*t^2
v = v0 + a*t
Started from rest
1st segment: 1.4 miles in 4.65 seconds
2nd segment: 1.8 miles in 1.30 seconds
Assumption:
Constant acceleration during each segment, although different acceleration for the segements.
Solution:
First segment acceleration:
x = x0 + v0*t + 1/2*a*t^2
x = 1.4 miles; x0 = 0 (starting from here); v0 = 0 (starting from rest); t = 4.65 sec
1.4 = 1/2*a*4.65^2
solving: a = 1.4/10.81125 ~= 0.129 miles/sec^2
Final speed at end of first segment:
v = v0 + a*t
v0 = 0 (starting from rest); t = 4.65 sec; a ~= 0.129 miles/sec^2
v ~= 0.129*4.65
solving: v ~= 0.602 miles/sec or 2167 mph
Second segment acceleration:
x = x0 + v0*t + 1/2*a*t^2
x = 1.8 miles; x0 = 0 (starting from here, or we could add 1.4 to this and x); v0 = 0.602 miles/sec; t = 1.3 sec
1.8 = 0.602*t + 1/2*a*1.3^2
solving: a = 1.0172/0.845 ~= 1.204 miles/sec^2
Final speed at end of second segment:
v = v0 + a*t
v0 = 0.602 miles/sec; t = 1.3 sec
a ~= 1.204 miles/sec^2
solving: v ~= 2.17 miles/sec, or 7800 mph
Thus assuming constant acceleration, we actually achieve a velocity greater than 6400 mph. With decreasing acceleration (a real-world condition), 6400 mph is a believable result.
Re:In Britain .. (Score:5, Informative)
Are there even human beings "driving" it?
I think it's safe to say "no"
if there were humans driving it at the start then there wouldn't have been at the end. apart from the fact that the sled stopped yb hitting an immobile object, the humans would have been but a red paint job at the back of the cabin by then anyways
Not this time, anyway. Although over at the International Space Hall of Fame [spacefame.org], only about 15 miles from where the above test occured, is the rocket sled ("Sonic Wind 1") that John Stapp [spacefame.org] rode in 1954 at the same testing grounds when he earned the title "Fastest Man Alive". Granted that was only 632 mph, but he did sustain a deceleration of around 40 Gs that reportly forced his eyes partially out of their sockets.
The forces on this particular test would have easily killed a human, so it's safe to assume that this one was riderless.
[I'm a former Space Hall tour guide, just sharing some trivia..]
Re:In Britain .. (Score:3, Informative)
6400 mph = 33,792,000 ft/hr = 9386.66 ft/sec.
9386.66 ft/sec divided by 6 seconds gives 1564.44 ft/sec/sec.
1G = 32 ft/sec/sec.
The acceleration felt by any passenger would have been 49G. No human could come close to surviving this.
If the "UK has been experimenting with trains using this technology", then I think such trains are unsafe. Maybe they are working on trains based upon rocket technology, or even working on trains based upon ideas from a similair experiment, but saying that they are working on "trains using this technology" makes no sense at all.