The abrupt ending of a spinning disk. (11th September 2019)

• Record Type: Journal Article
• Authors: Cross, Rod
• Is Part Of: European journal of physics. Volume 40:Number 6(2019:Nov.)
• Publication Date: 2019-09-11
• Subjects: precession -- rolling friction -- Euler's equation; Physics -- Periodicals; Physics -- Study and teaching (Higher) -- Europe -- Periodicals; 530
• DOI: 10.1088/1361-6404/ab26dc
• Languages: English
• ISSNs: 0143-0807

Abstract

Abstract: A disk that spins on a horizontal surface precesses about a vertical axis at a frequency that increases with time until the disk comes to an abrupt stop. The latter effect was investigated by attaching a piezoelectric disk to a spinning steel disk to monitor the vertical acceleration of a point near the edge of the disk. The amplitude of the acceleration remained constant, despite the increase in precession frequency, until just before the disk came to a sudden stop. The sudden stop appears to be due to a rapid increase in the coefficient of rolling friction, combined with a rapid increase in the offset distance of the normal reaction force, when the angle of inclination is very small.