  With the purpose of explaining recent experimental findings, we study the
distribution $A(\lambda)$ 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.
The problem of finding $A(\lambda)$ is equivalent to a First-Passage-Time
problem for a one-dimensional random walk with nonzero drift, whose exact
solution is well-known. From the exact solution of this problem we conclude
that: a) for inclination angles $\theta$ less than $\theta_c=\tan(\av{\mu})$
the average traversed distance $\av{\lambda}$ is finite, and diverges when
$\theta \to \theta_c^{-}$ as $\av{\lambda} \sim (\theta_c-\theta)^{-1}$; b) at
the critical angle a power-law distribution of slidings is obtained:
$A(\lambda) \sim \lambda^{-3/2}$. Our analytical results are confirmed by
numerical simulation, and are in partial agreement with the reported
experimental results. We discuss the possible reasons for the remaining
discrepancies.
