1. The problem statement, all variables and given/known data Consider a circle with radius [itex]r[/itex] diagrammed as the unit circle, but take only the second quadrant. On this quarter of the circle lies a chain with mass per unit length [itex]\rho[/itex] (the length of the chain is [itex]\pi r/2[/itex]). If [itex]\theta[/itex] is the angle made with the vertical axis at any point on the circle, determine the velocity [itex]v[/itex] of the last piece of chain that falls at any arbitrary point in [itex]\theta[/itex]. Ignore friction. The chain starts at rest. 3. The attempt at a solution I know using work/energy will make life easier here: [tex]\Delta V_g+\Delta T=0[/tex] looking for [itex]\Delta V_g[/itex] is the tough part (change in gravitational potential). my thoughts were to look at an infinitesimal piece of chain [itex]\rho r d\theta[/itex] and then try to figure out how the height changes as [itex]\theta[/itex] changes. I think [itex]\Delta H[/itex], where [itex]H[/itex] is height of a piece of chain, is [itex]cos\theta_1-cos\theta_2[/itex]. From here, modeling went sour. Hopefully someone can help me out! Thanks!