- #1
phyzzle
- 22
- 0
I am a little confused about why a passenger truck like a Chevy 2500 or a Ford F250 requires brake rotors with larger diameters than a car like a Toyota. I have a degree in Physics, and although I have not used it in 10 years I specifically remember learning that mass does not effect braking distance. The reason is as follows. A car stops due to frictional force between road and tire. When comparing stopping distance between two cars any difference in mass can be ignored because a greater momentum in a car with greater mass will also have a greater frictional force by the same magnitude, since friction equals normal force times co-efficiant of friction (kinetic or otherwise). For example if you have 2 Toyota Camrys and one is made out of aluminum and the other iron and they are allowed to coast to a stop from an initial velocity of 60mph they will come to rest at the same time. I understand that mass distribution plays a role in 18 wheelers, but assuming mass is distributed uniformally why does a truck need bigger brake rotors?
Paul Tippler's College Physics Text shows mathematically that mass cancels when calculating stopping distance.
Thanks!
Paul Tippler's College Physics Text shows mathematically that mass cancels when calculating stopping distance.
Thanks!