Re: Tire marks on road

["David T. Marx" <dtmarx@SIU.EDU>]

Here's my take on it.  As the wheels slid along the road surface, the
interfacial temperature increases with sliding.  The temperature
increase facilitates the transfer of rubber to the road surface.  Thus,
you would have darker marks at the end of the skid than at the
beginning.

This also reminds me of the drag racers that spin their wheels at
the starting line to put rubber on the track surface.  This increases
the friction coefficient.

Take care,
David Marx
Southern Illinois University

> A tire mark on a road due to hard braking is dark at one end and fades
> out at the other.  Which way was the vehicle moving when the brakes were
> slammed?
>
> This morning I wondered when I saw such marks.
>
> Hasan Fakhruddin
> Instructor of Physics
> The Indiana Academy for Science, Mathematics, and Humanities
> BSU
> Muncie, IN 47306
> E-mail: hfakhrud@bsu.edu
>
> This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.