Question

When 633-nm light shines on a fracture-line crack in a thin piece of metal, a diffraction pattern is observed on a screen located L = 0.90 m from the metal.

Problem 34.55 Part A When 633-nm light shines on a fracture-line crack in a thin piece of metal, a diffraction pattern is observed on a screen located L 0.90 m from the metal. If the width of the central bright fringe is w = 12 mm what is the width of the crack in the metal? Express your answer with the appropriate units. a= 1 Value Units Submit My Answers Give Up

Answer 1

width of the crack = a= m*lambda*L/w

where L= screen distance, w =width of central bright fringe , m=1

a= (633*10^-9*0.9)/0.012 = 47.5 micro-meter