Answer Happy

As an admirer of Thomas Young, you perform a double-slit experiment in his honor. You set your slits 1.21 mm apart and position your screen 3.53 m from the slits. Although Young had to struggle to achieve a monochromatic light beam of sufficient intensity, you simply turn on a laser with a wavelength of 647 nm. How far on the screen are the first bright fringe and the second dark fringe from the central bright fringe? Express your answers in millimeters. first bright fringe: mm second dark fringe: mm