# Difference between revisions of "Angle of friction"

Given two surfaces, the angle of repose between the two surfaces is defined as the angle $\theta$ that a fixed inclined plane made up of one surface must make with the horizontal so that a body with the second surfaces placed on it just starts slipping.
$\! \theta = \tan^{-1}(\mu_s)$
where $\mu_s$ is the limiting coefficient of static friction.