A student holds a laser that emits light of wavelength 639.6 nm. The laser beam passes though a pair of slits separated by 0.200 mm, in a glass plate attached to the front of the laser. The beam then falls perpendicularly on a screen, creating an interference pattern on it. The student begins to walk directly toward the screen at 3.00 m/s. The central maximum on the screen is stationary. Find the speed of the 50th-order maxima on the screen.