a horizontal table reported by Farkas et al.[Phys. Rev. Lett. 90, 248302 2003 PRLTAO 0031- 9007 10.1103/PhysRevLett. 90.248302] shows that the disk always stops sliding and spinning at the same instant with a terminal speed ratio ϵ 0= v/R ω= 0.653. We show that different terminal behaviors can be found when one considers the motion of a two-tier disk with lower section thickness H 1 and radius R 1, and upper section thickness H 2 and radius …
Analysis of the frictional motion of a uniform circular disk of radius sliding and spinning on a horizontal table reported by Farkas et al. [Phys. Rev. Lett. 90, 248302 2003PRLTAO0031-900710.1103/PhysRevLett.90.248302] shows that the disk always stops sliding and spinning at the same instant with a terminal speed ratio . We show that different terminal behaviors can be found when one considers the motion of a two-tier disk with lower section thickness and radius , and upper section thickness and radius . The terminal motion may be analyzed in terms of the normalized radius of gyration . It is found that while translation and rotation cease simultaneously, their terminal ratio either vanishes when , is a nonzero constant when , or diverges when . Experiments performed with plastic disks sliding on a nylon fabric stretched over a horizontal plate qualitatively corroborate the three different types of terminal motion.