title: Infinite penetration of a projectile into a granular medium.
abstract: An object falling in a fluid reaches a terminal velocity when the drag force and its weight are balanced. Contrastingly, an object impacting into a granular medium rapidly dissipates all its energy and comes to rest always at a shallow depth. Here we study, experimentally and theoretically, the penetration dynamics of a projectile in a very long silo filled with expanded polystyrene particles. We discovered that, above a critical mass, the projectile reaches a terminal velocity and, therefore, an endless penetration.
authors.affiliation: CINVESTAV-Monterrey, PIIT, Nuevo León, 66600, Mexico. fpacheco@mda.cinvestav.mx
authors.forename: F
authors.initials: F
authors.lastname: Pacheco-Vázquez
authors.forename: G A
authors.initials: GA
authors.lastname: Caballero-Robledo
authors.forename: J M
authors.initials: JM
authors.lastname: Solano-Altamirano
authors.forename: E
authors.initials: E
authors.lastname: Altshuler
authors.forename: A J
authors.initials: AJ
authors.lastname: Batista-Leyva
authors.forename: J C
authors.initials: JC
authors.lastname: Ruiz-Suárez