A small object A is held against the vertical side of the rotating cylindrical container

A small object A is held against the vertical side of the rotating cylindrical container of radius r by centrifugal action. If the coefficient of static friction between the object and the container is μs, determine the expression for the minimum rotational rate ⋅ θ = ω θ·=ω of the container which will keep the object from slipping down the vertical side.