In cricket and tennis (and I imagine baseball), the speed of the ball is often measured in mph (though when England is playing cricket in Australia, km/h are sometimes shown). These could (and should) be converted to m/s - I have never seen a cricket ball or a tennis ball travel for one kilometre (and certainly not one mile) under its own steam.
-----Original Message----- From: owner-u...@colostate.edu [mailto:owner-u...@colostate.edu] On Behalf Of mech...@illinois.edu Sent: 30 March 2010 19:25 To: U.S. Metric Association Subject: [USMA:47001] Re: FW: Special Employee Advisory: Message from Joe Boardman Wind speeds and the speeds of athletes (runners and swimmers) are easily visualized and can be understood in m/s by the general public, and even vehicle stopping distances and times for safety from speeds in m/s are reasonable. There is no good reason to discard speeds in m/s in favor of km/h. The planning of long trips and travel times is usually done at leisure, not in emergencies. Coherent SI units are best. ---- Original message ---- >Date: Tue, 30 Mar 2010 04:56:01 -0700 (PDT) >From: "John M. Steele" <jmsteele9...@sbcglobal.net> >Subject: [USMA:47000] Re: FW: Special Employee Advisory: Message from Joe Boardman >To: "U.S. Metric Association" <usma@colostate.edu> > > For a train, plane, car, etc, I recommend we NOT > belabor "coherent units" and just focus on using > correct symbols, km/h. I can pretty well guarentee > the public DOESN'T want to know the speed in meters > per second and carry out a division by 3.6 (or 3600) > to estimate "when do we get there." > > You are certainly (technically) correct that > kilometers per hour isn't coherent units. However, > for the most common calculation done with the data, > it is more useful in everyday life. That is > probably why the BIPM explicitly allows the hour to > be used with the SI. > > If AP doesn't accept the authority of the SI > Brochure, NIST SP330 and SP811, etc, there is not > much we can do to convince them. Since the AP Style > Guide requires online subscription or purchase, I > don't have it. But we need someone who has it to > analyze it's metric usage against the defining SI > documents and call the errors to AP's attention. It > might also make sense to check whether the > Government Printing Office is correct on the same > points that AP is wrong on. That might strengthen > the case. > > ------------------------------------------------ > > From: "mech...@illinois.edu" <mech...@illinois.edu> > To: U.S. Metric Association <usma@colostate.edu> > Sent: Mon, March 29, 2010 8:43:20 PM > Subject: [USMA:46998] Re: FW: Special Employee > Advisory: Message from Joe Boardman > > Of course, speed in SI is in units of m/s or in its > multiples by SI prefixes, e.g. km/s of a spacecraft. > "km/h" is not coherent SI, and "kph" is *certainly > not acceptable* in any version of units. Who has the > clout to correct the AP? > ---- Original message ---- > >Date: Mon, 29 Mar 2010 19:28:54 -0400 > >From: "Carleton MacDonald" <carlet...@comcast.net> > >Subject: [USMA:46997] FW: Special Employee > Advisory: Message from Joe Boardman > >To: "U.S. Metric Association" <usma@colostate.edu> > > > > Arrrgh. The Associated Press Stylebook strikes > > again ... > > > > > > > > Carleton > > > > > > > > From: MacDonald, Carleton > > Sent: Monday, March 29, 2010 12:59 > > To: Employee Communications > > Subject: RE: Special Employee Advisory: Message > from > > Joe Boardman > > > > > > > > The Associated Press Stylebook is rather clueless > - > > in fact, flat-out wrong - on a number of issues > > regarding metric measure, and this is one of the > > more egregious ones. > > > > > > > > For one thing, there is no unit of distance > called a > > "k". Capitalized, "K" is the SI (International > > System of Units = the metric system) symbol for > > "Kelvin", the base unit of thermodynamic > > temperature. This is of course not what is meant > > here. The unit of length being used here is the > > kilometer, and its symbol - its only symbol - is > > "km", and the way to show distance over time is > > "km/h". "kph" in SI is meaningless, but no doubt > > they're deriving it from "mph", under the wrong > > assumption that as the "m" stands for "mile", the > > "k" stands for "kilometer". > > > > > > > > The fact that AP and many other users have no > idea > > how to properly express metric units has other > > examples too, such as "5K" road races (a 5-kelvin > > race?). > > > > > > > > All of this of course stems from the fact that > the > > USA stubbornly resists joining the rest of the > world > > in measuring intelligently. > > > > > > > > That said: at least we mentioned the speed in SI > as > > well as in old units, and that is good. > > > > > > > > Carleton MacDonald > > > > > ---------------------------------------------------- > > > > From: Employee Communications > > Sent: Monday, March 29, 2010 10:41 > > To: MacDonald, Carleton > > Subject: RE: Special Employee Advisory: Message > from > > Joe Boardman > > > > > > > > Thanks for the input. But, according the > Associated > > Press Stylebook, kph is acceptable in all > > references. > > > > > > > > Kevin > > > > > > > > > ---------------------------------------------------- > > > > From: MacDonald, Carleton > > Sent: Friday, March 19, 2010 3:38 PM > > To: Employee Communications > > Subject: RE: Special Employee Advisory: Message > from > > Joe Boardman > > > > > > > > One tiny minor thing: kilometers per hour is > > expressed "km/h". > > > > > > > > > ---------------------------------------------------- > > > > From: Employee Communications > > Sent: Friday, March 19, 2010 15:32 > > Subject: Special Employee Advisory: Message from > Joe > > B. > > > > > > > > Attached is a Special Employee Advisory from > > President and CEO Joe B.. Please post on all > > bulletin boards. > > > > > > > > special employee advisory > > > > March 19, 2010 > > > > > > > > > > > > Dear Co-workers, > > > > > > > > <snip> > > > > > > > > Specifically, this department will work on the > > planning and development activities that will > allow > > us to significantly increase operating speeds > above > > 150 mph (240 kph) on the Northeast Corridor. It > will > > also pursue partnerships with states and others > in > > the passenger rail industry to develop > > federally-designated high-speed rail corridors > such > > as the new projects moving forward in California > and > > Florida. > > > >
