posted by Paige .
Light from a helium-neon laser (wavelenght = 633 nm) is used to illuminate two narrow slits. The interference pattern is observed on a screen 3.0 m behind the slits. Thirteen bright fringes are seen, spanning a distance of 52 mm .
Part A -
What is the spacing (in mm ) between the slits?
Express your answer using two significant figures.