A bar of mass m = 0.50 kg lying on a horizontal plane with a friction coefficient k = 0.10 is attached to the wall by means of a horizontal non-deformed spring. The stiffness of the spring is equal to x = 2.45 N/cm, its mass is negligible. The bar was displaced so that the spring was stretched by x0 = 3.0 cm, and then released. Find:
(a) The period of oscillation of the bar;
(b) The total number of oscillations that the bar performs until it stops completely.