20.5.3
The generalized force of the mechanical system Qφ = -20sinφ, where Q? In N • m; Φ is the generalized coordinate, rad. Determine the angular acceleration φ at the time when the angle φ = 3 rad, if the kinetic energy of the system is T = 5φ2 + 30 sinφ • φ. (Answer -0.282)