Chapter 11, Problem 50P

The rotor of an electric motor has rotational inertia I_m = 2.0 × 10⁻³ kg·m² about its central axis . t he motor is used to change the orientation of the space probe in which it is mounted. The motor axis is mounted along the central axis of the probe; the probe has rotational inertia I_p = 12 kg·m² about this axis. Calculate the number of revolutions of the rotor required to turn the probe through 30° about its central axis.