11. On the bench Zhukovsky man standing and holding a thin rod located vertically along the axis of rotation. Bench person rotates at n1 = 9 rev / min. With what frequency n2 will rotate the bench with a man, if you turn the rod so that it took a horizontal position? The total moment of inertia of human and benches Jz = 5 kg • m 2, the length of the rod ℓ = 2 m, mass m = 3 kg. The center of mass of the rod resides at the axis of rotation.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)