Problem 1.123

Two bars of masses \(m_{1}\) and \(m_{2}\) connected by a non-deformed light spring rest on a horizontal plane. The coefficient of friction between the bars and the surface is equal to \(k .\) What minimum constant force has to be applied in the horizontal direction to the bar of \(\mathrm{m}\) ass \(m_{1}\) in order to shift the other bar?