Problem 1.184

A chain \(A B\) of length \(l\) is located in a smooth horizontal tube so that its fraction of length \(h\) hangs freely and touches the surface of the table with its end \(B\) (Fig. 1.47\()\). At a certain moment the end \(A\) of the chain is set free. With what velocity will this end of the chain slip out of the tube?