i suppose is friction, is the coefficient of friction, and is the force in Newtons? Well, no, they would use for force right? what do the variables mean?
Sorry! I guess I wrote that for only the original poster, didn't I?
where is the force of friction is the coefficient of rolling friction (typically much less than the coefficient of kinetic friction.)
N is the normal force on the object between the pair of surfaces inducing the friction.