Yep, It is the speed. However, if you always accelerate hard you will spend more time cubing your higher speed as drag losses, than if you take it easy and go easy cubing a lower speed for a longer time.
So, take it easy speeding up, and get on the regen hard to slow down (reduce that cubed high speed as much as possible). On Thu, Nov 6, 2014 at 1:41 PM, Robert Bruninga via EV <[email protected]> wrote: > > Slower acceleration leads to lower average speed. > > Which leads to lower wind losses. > > Not at tall. You can take all the time y ou want to get to 70 PMH, but it > is not acceleration that is causing the wind loss, it is *speed*. > > The wind losses are proportional to the cube of *speed* period. You can > accelerate to a high speed or you can coast down a hill, in either case, > it is *speed* that is the only variable we are talking about there. The > fact that acceleration causes speed is a second-order effect. And just > confuses the layman.... > > Bob > > > -----Original Message----- > From: Willie2 [mailto:[email protected]] > Sent: Thursday, November 06, 2014 9:51 AM > To: Robert Bruninga; Electric Vehicle Discussion List > Subject: Re: [EVDL] Range vs Speed > > Generally, correct. > > On 11/06/2014 07:49 AM, Robert Bruninga via EV wrote: > > Energy used in driving is simple physics: > > > > Everything you put into acceleration you get back in Momentum. > > Everything you put into a hill, you get back as potential energy. > > Everything you put into braking is LOST (regen gains some back). > > Wind resistance goes up as the cube of speed. > True, but.... I believe, per unit distance traveled, energy lost to wind > friction goes up with the square of the speed. That is, in a given amount > of time, you cover more distance at high speed than at lower. > You experience the higher wind resistance for a shorter period of time. > > > > So the only real control you have over energy is keeping the speed > > (wind > > resistance) down. > > > > Gas cars are actually MORE efficient at high acceleration when the > > throttle plate is wide open and the pumping losses are minimized. So > > creeping away from a traffic light does not really gain anything. > > BUT, if it is a typical gas car and the engine then keeps running > > during the coast phase, that too is 100% waste (engine running but doing > nothing). > > > > When people say go "light on the accelerator" they are not talking > > about the rate of acceleration at all. They are talking about DON'T > > OVER ACCELERATE beyond what it takes to coast to the next stop without > > having to use the brakes. > Slower acceleration leads leads to lower average speed. Which leads to > lower wind losses. > _______________________________________________ > 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 [email protected] <[email protected]> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20141106/a268e396/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)
