In the rotating disk and strobe demo, we observed that different flashing rates of the str...

In the rotating disk and strobe demo, we observed that different flashing rates of the strobe light would make the spot on the disk stand still.

(a) Assume that the disk is rotating in the counterclockwise direction at a constant speed of 12 rev/s. Express the movement of the spot on the disk as a rotating complex phasor.

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(b) If the strobe light can be flashed at a rate of n flashes/s, where n is an integer greater than zero, determine all possible flashing rates such that the disk can be made to stand still.

Note: The only possible flashing rates are 1 per second, 2 per second, 3 per second, etc.

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(c) If the flashing rate is 13 times/s, explain how the spot moves, and write a complex rotating phasor that gives the position of the spot at each flash.