Thread: Tension in circular motion

Given a question" A metal ring of mass m and radius R is placed on a smooth horizontal table and is set rotating about its own axis in such a way that each part of the ring moves with a speed v.Find the tension in the string".In solution there is a tension T acting on a point on the ring in tangential direction.How is it possible? Since metal ring is rotating in circular path then tension must be radial.

That is an interesting problem. Imagine that you were to cut the ring in half. The half of the ring to the left of the cut would tend to fly off to the left, due to centrifugal force, and the half to the right of the cut would fly off to the right. You could solve for the total force pulling the half of the ring to the right by summing (integrating) the x components of the force on each particle of the ring to the right of your imaginary cut. This force would be 2 times the tension.