Help Proove Physics Teacher Wrong

I'll give contribute this (which is probably what the instructor is getting at)...

fs < us n

fk = uk n

fs = magitude of static frictional forces
fk = magnitude of kinetic frictional forces
us = static coefficient of friction (usually this is a 'look-up' value)
uk = kinetic coefficient of friction (usually a 'look-up' value)
n = normal force of the object. For example the Force of tires on the concrete, or Force of a brake pad on a rotor.

There is no allowance for the surface area of the contact area, when calculating the Frictional Forces.

The above works on the assumption that the 2 surfaces are 'hard'





The following explains a little as to how 'soft' surfaces are different...
http://www.school-for-champions.com/science/friction_equation.htm


Basically, hard surfaces are simpler to work with mathematically, which is why these equations are used in 101 level physics classes.

Soft surfaces are much tougher to work with.


jason



All i got outta that was F and U :D