Sunlight filtered through a narrow‐band green filter (central wavelength 550 nm) strikes two slits separated by 0.25 mm. A white sheet of paper is held 1.8 m beyond the slits so the interference pattern can be measured.
(a) Calculate the angle, measured from the central bright region, at which the second bright region of constructive interference appears.
(b) Determine the distance on the paper between the central bright region and this second bright region. Express your answer in centimetres.