Re: Friction and area.

["Rick Tarara" <rbtarara@sprynet.com>]

Yes, the larger surface area dissipates the heat energy better and prevents
the tires from melting.  The coefficient of friction between rubber, liquid
rubber, and asphalt is rather small.  On the other hand, the coefficient
between rubber and rubber (or whatever substitutes for rubber these days) is
higher than between rubber and asphalt and consequently the drag racers
purposely melt rubber in the start area (the burn-out) then give it time to
cool and solidify, then position themselves at the start line with their
rear tires sitting on the deposited rubber.

Rick

-----Original Message-----
From: Doug Craigen <dcc@cyberspc.mb.ca>

> Somebody else mentioned the large tires on race cars.  Isn't this at
> least partly to reduce frictional heating and also due to acceleration
> considerations (same torque, larger radius => more acceleration)?