Quote:
Originally Posted by 157db
Its called centrifical force.
|
Actually, such a force doesn't exist. Try reading a physics manual next time.
It's the tendency for any object along a rotation path to want to stray from the path of rotation at a tangent. A force is produced from accelerating this object, in the case of a tire: it's tread, is really the force that causes the tire to want to expand upward/outward. We commonly refer to this phenomena as
centripetal force.
An object along a rotational path is always under acceleration by definition. The rotational velocity rate of change determines the acceleration, therefore, at higher speeds, a tire is experiencing a larger force on the tread that is wanting to stray tangent from the tires, which is what causes the tire to expand.
Chemistry would also show that as a tire experiences friction, heat produced from the friction will cause pressures to rise. I'm pretty sure it's safe to deduce that pressures are assumed as constant under these sort of tests.