Curmudgeonly & Skeptical presents Boned Jello: Speed Limits

Thursday, October 13, 2011

Speed Limits

One thousand 1
One thou

“

From my sailing days I knew that my Cal 25 had a maximum speed of 6.29 knots. An immutable law of physics.

Maximum Hull Speed = 1.34 * LWL^1/2
LWL: Boat Length at Water Line

Watching Top Gear, which bench marks car's 0-60 mph times, I've become acutely aware of and astounded by advances in these times. Just awhile ago the Bugatti Veyron did it in 2.5 seconds! Think of that. You're sitting at a stop light.

It changes to Green.
You floor it.
Repeat after me,
One thousand 0ne
One thousand two
One thous — Whoa!
You're doing 60 miles an hour.

Now comes the Barabus, a new 1005 horsepower supercar the automaker says is capable of doing zero to 60 mph in 1.67 seconds. HMFS!

Is there a physical law that comes into play here? A point where a car may go no faster? The same goes for things like the fastest running mile. When Roger Bannister broke the 4 minute mile in 1954 the world was astounded. Hicham El Guerrouj is the current men's record holder with his time of 3:43.13 minutes. We know absolutely that someone will beat that. What's the limit? Can someone run it in 2 seconds? Why not?

My brain hurts.

”

Rodger the Real King of France 10/13/2011 12:44:00 PM 14 Comments

"If the number of Islamic terror attacks continues at the current rate, candlelight vigils will soon be the number-one cause of global warming. "
Argus Hamilton

14 comments:

Anonymous said...: I love the Cal 25. It is the perfect day sailer. I remember the military marina selling off the old gals for a pittance... a couple hundred bucks a piece. They replaced them with new Catalinas, and it never was the same.

Casca; 10/13/11, 1:00 PM
BlogDog said...: "We don't serve faster than light particles in here!" said the bartender. A neutrino walks into a bar.; 10/13/11, 1:02 PM
leelu said...: Rog,

Basic aerogodamnics - drag vs thrust.

Think of the F-4... proof that, if you have a big enough engine, *anything* can fly.; 10/13/11, 1:13 PM
Rodger the Real King of France said...: day sailerZ? - sleeps 6; 10/13/11, 1:38 PM
Ole Phat Stu said...: @BlogDog : that is an absolutely BRILLIANT line! I'm stealing it ;-); 10/13/11, 1:45 PM
Anonymous said...: Well, here's one physical law. If (0) acceleration force only comes via the drive train (i.e. no JATO units, no rubber flying off the back wheels) (1) a car has perfect friction at its driving tires, (2) all its weight is on its driving wheels, (3) it is not accelerating its front end up in a wheelie, and (4) (bad assumption) we ignore any extra downward force on the driving wheels from, for example, a spoiler, then the car can manage an acceleration equal to 1 G, i.e. 32.16 feet/second^2. At this rate of acceleration, it takes 2.74 seconds to reach 60 mph.

Since the Veyron and the Barabus (supposedly) both beat this time limit, assumption #4 must be wrong.; 10/13/11, 2:21 PM
drew458 said...: Something faster will come along, but it quickly becomes a matter of grip. You need massive tires made of soft sticky rubber to launch like that, and they wear out in nothing flat.

My 1984 Mustang GT needed 2 new rear tires every other year, and I was just driving it, not whomping on it. And those were top quality performance tires too. Today's 'stang has more than double the power of my old crate.

Anon - Assumption 4 IS wrong, but for other reasons: aerodynamics are almost meaningless at speeds under 60mph. Slippery won't hurt, but it doesn't help a whole lot either.; 10/13/11, 2:57 PM
Col Jerry USMC(ret.) said...: One factor never used in aerodynamic laws that I ever studied: When making a black night catapult launch from an aircraft carrier, all naval aviators are sure that flying speed comes mainly from "flapping buttocks"!

ur welcome,
ColJ; 10/13/11, 3:12 PM
Wabano said...: Dont forget the coke syrup spread on the raceway...Midget racecars have been doing that stuff for ages,
riding behind a thousand horsepower V-8,
under enormous sails pushing down the cars sticking on the coca-cola!
Beastly acceleration!Racing in circle driving sideway too!
http://www.xxxraceco.com/images/TeamXXX/Brian%20Montieth%20Win%2020111008%20(Lincoln)%20-%201.jpg
Funny, I flew once to BA with such a racer guy when a pallet of coke syrup collapsed
in the rear of the airplane, crushing a few barrels of syrup.
The horrible stuff spread by capillarity all the way to the front of the plane on the cargo floor.
Fact, I noticed it only when I took a piss in the portapotty and my feet got glued to the floor.
Company spent a million dollar trying to clean the DC-8 but gave up and junked it as the
phosphoric acid in the coke burned out the aluminium structure...
Think about it next time you drink a coke!; 10/13/11, 4:42 PM
Anonymous said...: I can't believe you'd quibble about such a thing. I'll be in dire straits when I sleep on a 25 footer.

"Any fool may carry-on. It takes wisdom to know when to shorten sail." ~Masefield

Casca; 10/13/11, 4:50 PM
renojim said...: Top fuel rails are going from 0 - 322 mph in less than 4 seconds these days. That's gotta' be some 4 seconds though.; 10/13/11, 5:53 PM
Anonymous said...: I remember reading about a guy named, Ken Stevens??? Drove a Ford Cobra 427 side-oiler, zero to 100 and back to a stop in something like 14 seconds? Memory is getting as fuzzy as my eyebrows.; 10/13/11, 8:22 PM
Fred Z said...: Yah, big deal. My used 2006 Suzuki sv650 motorcycle does 0-60 in 2.43 sec. Cost me $4,500.00.

It's not even a superbike.

You'll notice that 300K super cars pull in their horns mightily when they're at a stop light next to a motorcycle. The vrooom, vroom goes away.

Not even to mention the thrills of no belts, no bags, no bodywork, no nothing between you and the pavement.; 10/13/11, 11:27 PM
Anonymous said...: I had an old Hot Rod magazine from the 1950's with an article complete with graphs and mathmatical formulas proving that it was physically impossible for a vehicle to exceed a speed of 150 mph in a standing start 1/4 mile drag race.

Vlad-The-Inhaler; 10/15/11, 9:10 PM

Thursday, October 13, 2011

Speed Limits

14 comments:

Post a Comment