The Ascending Double-Cone: A Closer Look at a Familiar Demonstration
  The double-cone ascending an inclined V-rail is a common exhibit used for demonstrating concepts related to center-of-mass in introductory physics courses. While the conceptual explanation is well-known--the widening of the ramp allows the center of mass of the cone to drop, overbalancing the increase in altitude due to the inclination of the ramp--there remains rich physical content waiting to be extracted through deeper exploration. Such an investigations seems to be absent from the literature. This article seeks to remedy the omission. 
Sohang C. Gandhi, Costas J. Efthimiou