Jan first uses a Michelson interferaneter with the 606-nm light from a krypton-86 lamp. He displaces the movable mirror away from him, counting 818 fringes moving across a line in his field of view. Then Linda replaces the krypton lamp with filtered 502-nm light from a helium lamp and displaces the movable mirror toward her. She also counts 818 fringes, but they move across the line in her field of view opposite to the direction they moved for Jan. Assume lhat both Jan and Linda counted to 818 correctly.
(a) What distance did each person move the mirror?
(b) What is the resultant displacement of the mirror?