Light of wavelength 5.0 x 10-7m passes through two parallel slits and falls on a screen 4.0m away. Adjacent bright bands of the interference pattern are 2.0cm apart.
(a) Find the distance between the slits.
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light?