The following problems are to be solved using the principle of virtual work.ProblemThe bar...

The following problems are to be solved using the principle of virtual work.

Problem

The bar AB has mass m and length L. The spring is unstretched when the bar is vertical (α= 0). The light collar C slides on the smooth vertical bar so that the spring remains horizontal. Show that the equilibrium position α = 0 is stable only if 2kL >mg.