Light is incident normally on two narrow parallel slits a distance of 1.00 mm apart. A screen is placed a distance of 1.2 m from the slits. The distance on the screen between the central maximum and the centre of the n=4 bright spot is measured to be 3.1 mm.
a. a Determine the wavelength of light.
b. b This experiment is repeated in water. Suggest how the distance of 3.1 mm would change, if at all.