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From: carl@aoa.UUCP (Carl Witthoft)
Newsgroups: net.physics
Subject: Re: Question... [On tilt-meters in off-road vehicles]
Message-ID: <282@aoa.UUCP>
Date: Wed, 4-Sep-85 08:46:28 EDT
Article-I.D.: aoa.282
Posted: Wed Sep  4 08:46:28 1985
Date-Received: Fri, 6-Sep-85 04:21:32 EDT
References: <29@decwrl.UUCP> <10041@ucbvax.ARPA> <291@ecsvax.UUCP> <271@aoa.UUCP> <163@rtp47.UUCP>
Reply-To: carl@aoa.UUCP (Carl Witthoft)
Organization: Adaptive Optics Assoc., Cambridge, Mass. USA
Lines: 25

In article <163@rtp47.UUCP> throopw@rtp47.UUCP (Wayne Throop) writes:
>OK.  I went and looked at my Haliday&Resnick picture of a top
>precessing.  I'm still not enlightened.  In what way will this effect
>cause a car to be more stable turning left than right?
x
The wheels themselves have an angular momentum vector which points to the 
left (when the car is moving forward). Now, when you turn the car left
or right, these angular momentumvectors precess just like the top. There is 
a restoring force to match this effect. I'm far to fogyheaded to remember which
way the precession and force go, but you can check it out bysitting on a 
bar stool (the rotating kind), holding a bicycle wheel, spinning it up, then 
rotating the wheel on its axis. The stool (and you) will start to turn. 
Anyway, the point is that the car's turn in one direction or the other will
cause the wheels' precession to be such that the restorig force will act
against the overall centrifugal "force" which is trying to tip you over.
Hope this helps.



        Darwin's Dad (Carl Witthoft)
	...!{decvax,linus,ima,ihnp4}!bbncca!aoa!carl
	@ Adaptive Optics Assoc., 54 Cambridgepark Dr.
	Cambridge, MA 02140	617-864-0201
" Buffet-Crampon R-13 , VanDoren B-45, and VanDoren Fortes ."