> There was an amazing interview shown here last week involving
a Washington DC lobbyist for the "right to drive
huge gas-guzzlers" campaign, who was adamant that lighter cars are
inherently more dangerous in an accident, and even went as far as to say
that with a car with 4 people in it versus the same car with 2 people, the
2-people would be injured more because their car was lighter...

"Ya canna' change the laws of physics, Captain!"  - unless you're a
politician, apparently!
>>

The laws of Physics are slightly on his side in the altter case,
unfortunately. While the momentum change for both "vehicle systems" is
liable to be about the same the VELOCITY PROFILE for each vehicle will be
different. Take it to its extreme case and then look at the 2 and 4 person
case. A large heavily truck travelling at high speed impacting a small car
travelling at low speed will only slow slightly whereas the car will
suddenly assume a high velocoity in the reverse direction. The momentum
change for both will be the same. A person in each vehicle will have their
personal momentum (which is what concerns them) altered quite differently in
each case. The occupants' personal change in velocity is what matters to
them and their relative vehiclemass will have a bearing on this.

Taking the 2 person / 4 person case, the vehicle with the greatest MV treats
its passengers best *all other things being equal*. The important point to
note is all other things are not equal. Large vehicles are generally
designed to be stiffer and have less crumple zone protection. A 4Wd vehicle
will generally not 'fold up" in an accident the same way that a car designed
to do so will do so. The subsequent difference in peak acceleration forces
can have a significant effect on outcomes - which is why crumple zones
exist.


        RM












>
> > > I just wish I could convert the car to run on hot air - our 4 year old
son
> > > has far too much of it.
> >
> > My in-laws would drive for free, forever. 8-)
>
> A pipeline to the Houses of Parliament would be a really good source of
free energy!  :-)
>
> Cheers,
>
> Howard Winter
> St.Albans, England
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads