With the purpose of explaining recent experimental findings, we study the d
istribution A(lambda) of distances lambda traversed by a block that slides
on an inclined plane and stops due to friction. A simple model in which the
friction coefficient mu is a random function of position is considered. Th
e problem of finding A(lambda) is equivalent to a first-passage-time proble
m for a one-dimensional random walk with nonzero drift, whose exact solutio
n is well known. From the exact solution of this problem we conclude that (
a) for inclination angles theta less than theta(c)=tan([mu]) the average tr
aversed distance [lambda] is finite, and diverges when theta-->theta(c)(-)
as [lambda]similar to(theta(c)-theta)(-1); (b) at the critical angle a powe
r-law distribution of slidings is obtained: A(lambda)similar to lambda(-3/2
). Our analytical results are confirmed by numerical simulation and are in
partial agreement with the reported experimental results. We discuss the po
ssible reasons for the remaining discrepancies.