Quote:
Originally Posted by squirrel
Friction is weird, so yeah, you probably do have to derive a formula from empirical data.
An example of friction being weird: Most material interfaces have a higher coefficient of static friction, than of dynamic friction. But aluminum to aluminum has a higher coefficient of dynamic friction than static friction.
And when you consider automobile tires, think about what might be happening when the situation in my avatar occurs....
Good luck!
|
Although I'm only a high school student I must question your comment on aluminum on aluminum friction. If the static friction is lower then kinetic, this means as soo as you start movement with minimum force it will stop going back to static then starting again then moving imediatly back to static. Thus never moving at all, thus always staying as static friction. Am I missing something?
Also as an answer to the question
mu the mathmatical ratio of the force of friction/normal force is unique not only for every material but for every object. Thus, the contact area is calculated in when stating
mu. I couldn't give you a
mu of rubber on asphalt, but i could give you a
mu of a specific tire with a specific contact area and texture.
just as an explination of your source, I take Honors Physics and got a 20/20 on my friction quiz (no tests in this class) =P