A super-searchlight that is rotating at 120 rev/min throws its beam on a screen 50,000 miles away. What is, (a) the sweep speed of the beam across the screen, (b) the speed of a photon from the searchlight to the screen, and (c) the speed with which any particular photon sweeps across the screen? (d) any of these results violate the second postulate of the special theory of relativity? (The value of c is 186,000 mi/s).