A plank with a bar placed on it performs horizontal harmonic oscillations with amplitude a = 10cm. Find the coefficient of friction between the bar and the plank if the former starts sliding along the plank when the amplitude of oscillation of the plank becomes less than T = 1.0s.
When the bar is about to start sliding the plank, it experiences the maximum restoring force which is being provided by the limiting friction,
Thus
kN = mω02 a or, kmg = mω02a
