A beam of neutrons, all moving at the similar speed, is directed via a pair of slits whose centers are around 2.00 × 10-6 m apart. An array of detectors is positioned 49.9 m from the slits. The intensity pattern of received neutrons is calculated, and the first zero-intensity point is around1.76 mm off-axis. The mass of a neutron is around1.68×10-27 kg. (i) Determine the de Broglie wavelength of a neutron in the beam? (ii) Determine the speed of the neutrons in the beam?