Froude pendulum
The Froude pendulum is a self-excited mechanical pendulum . It consists of an arrangement with a closed rope to which a mass piece is fixed and a cylindrical horizontal axis over which the rope is placed. If the axle is set in uniform rotation, the rope is carried along by the axle due to the resulting static friction and the mass hanging at the lowest point is raised. The weight force, which is initially symmetrically distributed over both rope halves, is increasingly borne by one side. If the increasing rope force reaches the static friction force, the rope begins to slip on the axis and the mass moves downwards as a result of the gravitational pull. Sliding friction now acts between the axle and the rope ; it is smaller than the static friction. The shear stresses between the rope and the axle disappear when the mass is at the lowest point. Then the rope is taken along again by the static friction that is now acting again, which starts the next cycle.
See also
Individual evidence
- ↑ Spectrum of Science , December 2009