Solution of the A2 B7. Rotating with an angular speed of the rotor of the motor starts to decelerate the forces of aerodynamic drag, which currently is M = 12w2. The moment of inertia about the rotational axis J is = 150 kgm2. To determine the angle at which the rotor is rotated until the time when its angular speed is halved.

Right after the payment you receive a link to the archive with the solution of the problem in theoretical mechanics A2 B7 (condition 7) in the test book "theoretical mechanics" Dievskaya VA Malyshev IA 2009 for university students.
The decision is decorated in a format word (typed or hand-written decision in a Word), packed to the archive zip (open on any PC).

After checking the solutions I would be very grateful if you leave your positive feedback.