Halliday, Resnick & Walker — Rotation: Problem Problem_93

Strobing. A disk that rotates clockwise at angular speed \(10\pi \text{ rad/s}\) is illuminated by only a flashing stroboscopic light. The flashes reveal a small black dot on the rim of the disk. In the first flash, the dot appears at the 12:00 position (as on an analog clock face). Where does it appear in the next five flashes if the time between flashes is (a) \(0.20 \text{ s}\), (b) \(0.050 \text{ s}\), and (c) \(40 \text{ ms}\)?