Solve the following problem:
Problem: A single slit of width 0.2 mm is illuminated with a beam of laser light of wavelength 600 nm which casts a single slit diffraction pattern on a screen 6 m away.
Part I: What is the linear spacing between two successive fringes observed on the screen?
Part II: How far from the central bright fringe is the 4th dark fringe located?
Please use great detail in explaining the solution. Thanks.