For vehicle speed, km/h is easier to deal with because road distances are in km and this helps you estimate when you will get there or how long it would take. Distance 250 km, speed 80 km/h, it will take a bit over three hours.
Carleton -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Sunday, March 15, 2009 11:57 To: U.S. Metric Association Subject: [USMA:43888] Re: wind velocity Mark, Just as you do now, I have long advocated the SI unit of speed, m/s, for wind speed as well as for vehicle speed, for reasons of safety and metrication. Unfortunately, it is necessary to cement m/s tick markers on an analog speedometer, and no recourse for digital displays, until manufacturers provide a m/s option. Is m/s an option already in *any* vehicle instrument cluster? Gene. ---- Original message ---- >Date: Sun, 15 Mar 2009 04:04:24 -0800 >From: Mark Simon <[email protected]> >Subject: [USMA:43871] wind velocity >To: "U.S. Metric Association" <[email protected]> > > >The weather report predicts there will be a west wind with velocity of >28 km/h. I am going to ride my bicycle about 18 km towards the west >today. I cannot visualize 28 km/h, but I can visualize 7.8 m/s. This >means to me that I will get a better workout, going to my destination, >and should have an easier ride home. Would somebody please explain the >logic of measuring velocity in km/h? I do not understand why this is >done. I live in Southern California, and traffic is unpredictable >here. When I drive, I am only concerned with safety, and leave >additional time to get to my destination. If were are going to convert >to the metric system in the United States, why not consider using m/s >as the basic unit? I am usually only concerned with my velocity when >the traffic light turns yellow in front of me, and I have to make a >decision whether to decelerate or continue driving. If my velocity is >measured in m/s, that would make calculations simpler. In Europe, with >its denser populations, does measuring velocity in km/h work well in >calculations? I wager that highways are engineered using m/s >calculations. >Is it possible to get a velocimeter for a bicycle that measures in m/s? >
