This is a very basic problem which you all must have seen somewhere. But recently an itching doubt has come up to me regarding this problem. Problem: A chain lies on a table with some part of it hanging over the edge. Now if the coefficient of friction is μ, then find out the maximum part of the chain that can hang without sliding. The Usual Solution See the solution to the problem here: http://cnx.org/content/m14806/latest/ Confusion Now, in solving the problem, they considered the part of the chain on the table as "m1" and the hanging part as "m2". Then, they say that: μ*NormalForce = m2*g [itex]\Rightarrow[/itex] μ*m1*g = m2*g Now, my confusion is that why did they take normal force to be = m1*g?? Consider an FBD of the whole chain. Now the only force in the vertically above direction is the normal force. And it should balance all of the weight i.e. (m1+m2)*g. So according to me, normal force = (m1+m2)*g. However, all the solutions that I've seen take normal force = m1*g. But I just don't get it. Thanks in advance.