OldTryGuy

Anybody planning to be in Florida in April should consider X-Florida ride. 168 miles total with the first 100 miles easily done non-stop solo or with the crowd. Sub 5 hours not a problem either.

desconhecido 

20 m/h is about 29.33 ft/s

3.6 k/hr = 1 m/s

It's not a difficult to handle value range, it's just what people learn to use. If in the U.S., we used ft/s for highway speeds, everybody would understand that you go about a mile in one minute if you travel at about 90.

Likewise, if there were a country that used metric speeds for the highway, everybody would already understand what a 28 m/s speed limit meant.

desconhecido 

Back to the topic of this thread. Why wouldn't what we call a "metric century" be properly called a 0.1 Mm?

jfoobar

I always call them a 3.240779e-12 parsec ride.

Happy Feet

If...

You guys are losing sight of reality in your semantic arguments. Road speed is neither a purely imperial or metric measure and no one feels the need to be constrained by such rigidity. It is just distance over time. The commonly agreed upon base time unit for both is the hour and the measure is làrge enough to be manageable. In the US that's a mile and in metric countries it's a kilometer. You can argue it should be a meter all you want but saying you drive 10,000 meters per hour gets old real fast and prople will look at you funny. But not a good funny.

To argue one should say meters per second is like arguing one should say feet per second. Go ahead and knock yourself out but no ones going to do it. The second is to small a unit as is the foot or meter for practical application and in the end people adopt practical applications to common measures.*

Sorry, but that's just the way it is and millions of people in both worlds have no problem grasping it.
*

UniChris

If you're doing a physics problem the units are meters, kilograms, and seconds (MKS) or archaically, centimeters, grams, and seconds (CGS), otherwise the hour is included in SI as an unharmonized derived unit or some such "we recognize this illogical but entrenched tradition" gobbledegook.

Actually meters per second does yield practical numbers, but not as intuitively meaningful ones since it doesn't express transiting useful distance in times easily manually measured.

desconhecido 

I once tried to buy 500 g of salami in an Italian grocery store. That didn't work. So, I tried to buy .5 kilograms. No soap. I ened up buying 5 etti and everybody was happy.

Cyclist0108

Originally, the term century referred to a unit of time (100 years), rather than a distance, regardless of the unit (Å or furlongs).

Happy Feet

Not gobbledegook at all. That has a negative connotation that KPH as a measure does not deserve. Measures as well as language (and species) evolve. Scientific people should be the first to get that. To be practical a measure needs to be workable for the user group it is intended for. Collectively, every metric - centric country in the world has adopted KPH for some presumably practical reason. Would it not be intellectual elitism to suggest billions of people and their governments use gobbledegook as a basic daily measure.

Next up: Cranky English majors on literary forum argue people should say "I'll send you a text" instead of "I'll text you" because text is a noun not a verb. One man heard to exclaim: "You are all doing it wrong!"

Happy Feet

Tee Hee. This reminds me of a fun stunt to pull at Faculty mixers. Drop the term Irregardless into the conversation and watch the mental fists fly!

UniChris

The gobbledegook is not the measurement unit, but the specific categorization language by which it is incorporated with a held nose into SI, in recognition of the fact that despite breaking the design principle it is indeed practically useful.

I'd had the actual text of the terminology in front of me earlier in the day but didn't feel like digging it up again.

Happy Feet

But why a held nose for a measure that is both practical and universally workable? This thinking only pertains to a small select group relating the measure system from an unrelated field.

I jokingly referred to the English Major in my previous post but it is like one arguing against the use of common language words as if they, not the vast majority of people who actually engage in conversation, own the prerogative of the language system in use. In most cases, they are far removed from the day to day use of the very language they espouse as is anyone who thinks in terms of m/s when driving a car or riding a bike on a road.

Accepted norms are based primarily on.. accepted norms. One does not insist on driving on the right when visiting Britain because it is correct in the land of their origin.

jefnvk

Actually quite a few of my new automotive requirements and test specifications are starting to use m/s in place of MPH or KPH (which, frustratingly enough, are still used side by side in documents)

OBoile

I did not realise this was a distinction. Thanks for the info.

indyfabz

I picked up cycling as an adult in the late 80s. Metric century was used back then. You need better material.

Happy Feet

What are they measuring?

I eagerly await the first metric correct road signs to appear anywhere. I wonder how the usually mechanically precise Germans can stand it otherwise

jefnvk

Speed. Really annoying trying to convert m/s to a unit that displays on the dashboard, too!

Generally used in some sort of conjunction with an acceleration event (i.e., accelerate to 20m/s at a rate of 1m/s^2), but starting to be more frequently they are just standalone values.

Wildwood

superdex

And then there are those who turn it into a fundraising event: Fat Cyclist » Blog Archive » Now Open: 2016 100 Miles of Nowhere

cyccommute 

Live by hyper-accuracy, die by hyper-accuracy. First, the abbreviation of "mile" is "mi." so as not to be confused with meter. Second 20 m/h is not about 29.33 ft/s. It is about 30 ft/s. It could even be 29 ft/s if you assume that the zero in 20 is significant which it may or may not be. It would depend on context. 20.00 mi./h would be 29.33 ft/s but there is no "about" on that value. "About" should mean, well, about.

Second, 3.6 k/h is not 1 m/s. It is 1.0 m/s. The zero after the decimal isn't a place holder. It is an accurate and precise representation of the previous value. If you use 2 significant digits in the calculation, you use 2 significant digits in the answer unless there is some other measurement that is limiting the number of significant figures.

People in the US won't learn the damned metric system. I wonder how much they would howl if you asked them to use m/s.

Additionally, do your math! You don't go "about a mile in one minute at 90 mi./h. You travel one US statue mile in 1 minute at 60 mi./h. 90mi./h equates to about 40 sec/mi.

Eventually. There is a limitation to using meter per second. It's the precision of the speedometer. The speedometer in my car goes from 0 to 160 mi./h or 0 to 247 km/h. In m/s, the range would be from 0 to 68. 30 mph (I'm going to this convention because it's easier to type) is 48 km/h or 13 m/s. 55mph is 88 km/h or 24 m/s. 160mph is 247 km/h or 68m/s. The division on the speedometer would have to be very tiny to cover the range and would be difficult to keep on the proper speed. There's simply too much precision for an activity that doesn't require it.

Finally, to answer TiHabenaro's original question, there have been metric centuries around for a very long time. I have LAW patches going back to the late 70s that include the metric century (along with the quarter, half and double century and double metric) as part of events sanctioned by the LAW.

desconhecido 

Ah, yes indeed. Jr High physics measurement lesson. That's what we need.

fine -- got me there.

20 m/h ? First, the abbreviation of "mile" is "mi." so as not to be confused with meter.



Second, exactly 20 mi/h is exactly 29 1/3 ft/s -- so, you see, there is very much about.

What is 3.6 k/h supposed to be measuring? Whatever 3.6 k/h is, it's not 1.0 m/s

As for precision and significant figures in a non scientific, non engineering context, such as this one, well, you go girl.

Question, when someone asks you to convert 1 inch to metric do you invariably respond, "3 cm" . When you ask someone to convert 1.00 cm to inches you say, ".039 inches, and there is no about about it. . 'About' should mean, well, about."

Who suggested that they should be asked to use m/s? If you want to measure speed with a metric unit, m/s is a good choice. If you are using metric units, kph is not.

RTFM If we measured road speed in ft/s, when your speedometer measured 90, you'd be travelling about a statute mile in about a minute. That is, because, 90 ft/s is about 60 mph which is about 1 mile/minute. That which is about, by the way, includes that which is exact.


If your speedometer goes to 160 mph, then it must go to 260 km/hr by the standards which you are trying to enforce. And where does 247 km/hr and 68 m/s come from? No math with which I am familiar. As somebody recently said, "Do the math."

If road speeds were displayed on your speedometer in m/s, your scale could go from 0 to 70 or 0 to 75. With increments of 1 m/s, it wouldn't be a problem to keep on the proper speed. A digital display with .1 m/s precision would work. That, seems to me, is an entirely practical range. Perhaps my specific gravity is insufficient to identify the problem as you have.

Now, I understand that with your high specific gravity that you may not already understand this so I'll state it to be obvious. I am not suggesting that we measure highway speeds in m/s or ft/s or any other measure than that which is customary anywhere in the world. What I am saying is that the magnitude of the units is not the problem. Perfectly practical measurements could be done with either ft/s or m/s.

Oso Polar

It is actually a problem - but you are looking into the wrong unit. Kilometer is not a problem, hour is a problem. And not because it is not metric somehow - it is a problem because time measurement system is not decimal-based on units higher than second. We have perfectly good smaller time units: second, millisecond, microsecond etc. But we don't have ones of the higher capacity, like decasecond, hectosecond, kilosecond, megasecond etc., we use extremely antique time measures that use sexagecimal-based (base 60) numbering system which originated around 2000 BC. So far, no one was brave enough to introduce a complete time overhaul.

Oso Polar

Oh, to clarify why hour is a problem - because in the current situation we are left with just a second as the biggest "normal" unit alternative. And it is way too small for normal life. At least a minute or bigger unit is required and we don't have it.

desconhecido 

When the French established what is pretty much the metric system, they did try to implement a metric time system as well. There would be 100 minutes to an hour, ten hours to a day, ten days to a week. Looks like the second would have been redefined so that 100 new seconds would be exacly equal to 86 old seconds. It doesn't seem to have worked out and somehow we have muddled through.

Was recently watching a baseball game on TV and they talk about things in mph. Pitches being thrown at 90 - 100 mph, batted balls leaving the bat at 100 mph, and the like. That's sort of odd, to me, because typical baseball lengths are feet and times are seconds. (perhaps in Japan, Italy, Korea, and other "metric" countries in which American baseball is popular they use meters).

cyccommute 

[QUOTE=desconhecido;20407454]20 m/h ? First, the abbreviation of "mile" is "mi." so as not to be confused with meter.

Just using your units.

If you are saying "exactly" that is different from "about".

Again, just using your units. I assume that it is 3.6 kilometers per hour which works out to 1.0 m/s. Kilometers per hour is a perfectly valid measure of speed and is derived from SI units. That is allowed for all kinds of measurements.

You realize that this statement is highly offensive. "Girls" can be and are excellent scientists and engineers.

It would depend on the context. In casual conversation, I might say almost 2 and one half, which it is. And, if someone asked me to convert 1.00 centimeter to inches I would tell them that it was 0.394 inches. 0.039" is 1.0 millimeter. 1.00 mm is 0.0394".

You did because you insist that kilometer per hour isn't metric. It's not part of the SI system but it is a useful measure of speed.

My mistake. I didn't read that part of your post correctly.