I am pretty sure that friction of this kind means that we do not have to look on the forces as vectors. What the friction coefficient is, as far as I am aware, is the portion of a perpendicular force that is turned into friction, and friction is by definition a force that is directly opposed to...
Homework Statement
A casing of mass m can glide along a thin metal ring lying horizontally. It has an initial speed of v0. How long a distance s will it glide before stopping if its friction coefficient is μ?
The answer is given as
s = r/2μ * ln( v02 + √(v02 + g2r2)/ g * r )
The task is to...