# Re: A6 styling re A4/A8

```
>	I don't know the actual proportion.  Both of these factors
>certainly contribute.  I _do_ believe form Dynamics class, that the
>rotors will have more effect on braking than just their mass alone.  The
>fact that it is rotating makes it more important.  You may be right, that
>the vehicle mass is more important in this case, I don't know without
>seeing the numbers.
>
>Later,
>Graydon D. Stuckey

Yep, fer sure. You have to dissipate both the linear energy as well as the
rotational energy, so there is an additive effect to in/decreasing the mass
of the rotors, so what you say is 100% correct. My point is that this effect
is small as compared to the difference in the overall mass of the two
vehicles and any de/increase is swept area, and is very small as compared to
the relative mass and diam of the wheels and tires as their distance from
the axis of rotation is *much* larger Vs that of the rotors, hence *much*
larger angular momentum Vs the rotors, not to mention that the wheels &
tires are much more massive as well. The viper has huge wheels and tires
with enourmous angular momentum Vs those on the prowler. I'm sure one of our
mathematics&physics types could compute this for us with respect to the
brake rotors. We would need to know the mass and diam of the rotors on the
viper and on the prowler, F&R, to compute their angular momentum and compare
these values to the overall mass of the two vehicles in question, someone
posted the vehicle weight data here. Anyone up to the mathematics challenge?

-glen

```