21.1.20
The differential equation of small oscillations of a body has the form Iφ + сl2φ = lF. Determine the amplitude of the forced oscillations of the body in radial mode if the moment of inertia of it with respect to the axis of rotation is I = 6 kg • m2, the spring stiffness coefficient c = 3 kN / m, the size l = 0.5 m, the force F = 10sin6 πt. (Answer 3.62 • 10-3)