Granular material asteroids. Some examples of granular materials are snow, nuts, coal, sand, rice, coffee, corn flakes, fertilizer, and bearing balls. Research into granular materials is thus directly applicable and goes back at least to Charles-Augustin de Coulomb, whose law of friction was originally stated for granular materials. Granular materials are commercially important in applications as diverse as pharmaceutical industry, agriculture, and energy production. Powders are a special class of granular material due to their small particle size, which makes them more cohesive and more easily suspended in a gas. The soldier/physicist Brigadier Ralph Alger Bagnold was an early pioneer of the
Gravel Ridge, Arkansas $44,318. Males had a median income of $31,553 versus $21,903 for females. The per capita income for the CDP was $16,932. About 7.9% of families and 8.5% of the population were below the poverty line, including 10.6% of those under age 18 and 12.9% of those age 65 or over. The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Gravel Ridge has a humid subtropical climate, abbreviated "Cfa" on climate maps. Gravel Ridge, Arkansas Gravel Ridge is a former census-designated place (CDP) in Pulaski County,