What you experience is obviously correct, but why is the fun part. The work done and energy consumed are how to get at it.
If you start and stop at the same locations and take the same route, then changes in gravitational potential(height) wash out to 0. Then you are left with mass x acceleration, and frictional effects. Wind and air drag is the predominant loss and speed related - hence the wonderment about not much difference. Rolling resistance is not that big a deal, comparatively; though you can certainly quibble over rough roads and ire heating etc. The mass doesn't really change, so you have to think about acceleration.... Acceleration is the area under the velocity curve. It is intuitively a little hard to think about this, but nothing says the fast easy trip has the same rate of change of velocity as the slow speed up and slow down trip. I vote for this as the factor mitigating air drag in the comparison. Perhaps if you took it very easy on the slow run you would see the greater energy losses appear in the the fast run. If there is regen involved then you have to know a bunch of details about how that works - but it is a possibility. The energy recovered is likely to be different - the two very different trips. Another possible contribution is prevailing winds during the trips. I have seen careful work done with streamlined bicycles and this can be a confounding factor in coast down testing of drag on bodywork. For valid results you need dead air when comparing bodywork changes. If the the wind is in you face more on the slow run, and from the rear during the fast run.... On Thu, Nov 6, 2014 at 6:12 AM, Chris Tromley via EV <ev@lists.evdl.org> wrote: > I think people tend to generalize, thinking high speed must be > high-consumption and low speed low. As in most things, it depends. If you > rive for low consumption, high speed can be pretty economical. I've seen > this with my ICE vehicle watching the real time consumption readout, > sometimes see 50+ mpg at a steady, level 80 mph. Conversely, if your slow > return trip was filled with a bazillion starts and stops, each will take > more energy to accelerate the vehicle than a steady cruise. > > Chris > > On Thu, Nov 6, 2014 at 12:43 AM, John Lussmyer via EV <ev@lists.evdl.org> > wrote: > > > I'm not seeing much difference in power usage at different speeds. > > Last night, I drove 60 miles on the highway/freeway, almost entirely at > > 60mph. > > used 125AH out of my freshly charged pack. > > Tonight, I drove the return trip, taking almost an hour longer due to > > horrible slow traffic on the freeway. Often stopped or below 10mph. > > Same power usage. > > > > -- > > Tigers prowl and Dragons soar in my dreams... > > _______________________________________________ > > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > > For EV drag racing discussion, please use NEDRA ( > > http://groups.yahoo.com/group/NEDRA) > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/a28a36a3/attachment.htm > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA ( > http://groups.yahoo.com/group/NEDRA) > > -- Put this question to yourself: should I use everyone else to attain happiness, or should I help others gain happiness? *Dalai Lama * Tell me what it is you plan to do With your one wild and precious life? Mary Oliver, "The summer day." To invent, you need a good imagination and a pile of junk. Thomas A. Edison <http://www.brainyquote.com/quotes/quotes/t/thomasaed125362.html> A public-opinion poll is no substitute for thought. *Warren Buffet* Michael E. Ross (919) 550-2430 Land (919) 576-0824 <https://www.google.com/voice/b/0?pli=1#phones> Google Phone (919) 631-1451 Cell (919) 513-0418 Desk michael.e.r...@gmail.com <michael.e.r...@gmail.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/524028cd/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
