The angle of repose is the steepest free-surface angle at which a loose granular material remains static. A released dry granular pile therefore tends toward a conical surface with slope .
Articles by others on the same topic
The angle of repose is the steepest angle of descent or dip relative to the horizontal plane at which a material, such as gravel, sand, or soil, can rest without sliding. It is a measure of the stability of a pile of granular materials and is influenced by factors such as the shape, size, and moisture content of the particles.