Re: L2-"Negotiating" a curve.

[Bob Sciamanda <trebor@VELOCITY.NET>]

Let me add, this is the purpose of ABS braking systems (or judicial manual
braking) in turns, to forbid the cessation of wheel rotation and loss of
control.

Bob

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor

----- Original Message -----
From: Bob Sciamanda <trebor@VELOCITY.NET>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, November 03, 1999 11:59 PM
Subject: Re: L2-"Negotiating" a curve.


> No, not when you turn the wheels.  Let's presume the force IS only
> opposite to v; the (turned) wheel bearing will have a keel effect and
> allow only the component of this force in the turned direction to have a
> large effect.  Consider that if the wheel were locked (could not rotate)
> you would not turn - only skid forward.  The keel effect of the bearing
is
> real.
>
> Bob
>
> Bob Sciamanda (W3NLV)
> Physics, Edinboro Univ of PA (em)
> trebor@velocity.net
> http://www.velocity.net/~trebor
>
> ----- Original Message -----
> From: Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>
> To: <PHYS-L@lists.nau.edu>
> Sent: Wednesday, November 03, 1999 11:48 PM
> Subject: Re: L2-"Negotiating" a curve.
>
>
> > I would accept your argument if wheels were in water.
> > But this is not the case. The force from the road must
> > be opposite to v. Right?
> >
> > Bob Sciamanda wrote:
> >
> > > Yes, the analogy is a little strained, but not much.  Just as the
keel
> > > (perhaps, better, the rudder) reacts with the water, so the wheel
> through
> > > its interaction with the road allows the vehicle motion to be
> controlled
> > > internally ( by adjusting the wheel's rotational speed and
attitude),
> eg.
> > > by braking the wheel's rotational motion or by turning the wheel.
> > >
> > > Bob
> > >
> > > Bob Sciamanda (W3NLV)
> > > Physics, Edinboro Univ of PA (em)
> > > trebor@velocity.net
> > > http://www.velocity.net/~trebor
> > >
> > > ----- Original Message -----
> > > From: Ludwik Kowalski <KowalskiL@MAIL.MONTCLAIR.EDU>
> > > To: <PHYS-L@lists.nau.edu>
> > > Sent: Wednesday, November 03, 1999 11:30 PM
> > > Subject: Re: L2-"Negotiating" a curve.
> > >
> > > > Bob Sciamanda wrote:
> > > >
> > > > > ... The turned wheel is forced obliquely into the roadway,
giving
> > > > > rise to a reaction (frictional) force from the roadway.  The
front
> > > > > wheel bearing (and the wheel orientation) only allows the
> "forward"
> > > > >  (ie. in the turned direction) component of that force to be
> > > effective.
> > > > The "roadway" is along the y axis. Yes, there is a large sliding
> > > > friction force, in the direction of -y, resulting from steering.
But
> > > > that is all. The bearing is "deep inside", internal forces have no
> > > > effect on the motion of the C.M. The keel of a sailboat, on the
> > > > other hand, is in direct contact with the outside medium. Your
> > > > analogy does not seem to behelpful.
> > > > Ludwik Kowalski