Review | Constants An oil tanker spills a large amount of oil (n = 1.45) into the sea (n = 1.35). (a) If you look down onto the oil spill from overhead, what predominant wavelength of light do you see at a point where the oil is 380 nm thick? What color is the light? (b) In the water under the slick, what visible wavelength (as measured in air) is predominant in the transmitted light at the same place in the slick as in part (a)? How does the oil layer act on the incident light? Is there interference for a light with some wavelength in the reflected light, if light with the wavelength is prominent in the transmitted light? View Available Hint(s) The oil layer acts as a thick film; there is no interference. The oil layer acts as a thick film; there is destructive interference. The oil layer acts as a thin film; there is no interference. The oil layer acts as a thin film; there is constructive interference. The oil layer acts as a thin film; there is destructive interference. The oil layer acts as a thick film; there is constructive interference. Submit Previous Answers Correct Note that we cannot considered the oil layer as a thick film since we neglect the absorption of light in the oil and other optic effect there is in a thick film. The thickness of layer is about wavelength, so the approximation of thin film is very good for this case. If a wavelength is prominent in the transmitted light, there is destructive interference for that wavelength in the reflected light. Part B Choose the appropriate interference equations for reflected light that has the constructive interference that relates the thickness of the oil film and the wavelength of light. Check all that apply. View Available Hint(s) 2t=m (m=0,1,2,...), A = A/n. where n is the index of refraction of the oil. Ag and A are the wavelengths as measured in the air and in the oil respectively. 2t = (m+) (m = 0, 1, 2,...), A = /n, where n is the index of refraction of the sea water. Ag and A are the wavelengths as measured in the air and in the sea water respectively. = 2t=m (m=0,1,2,...), AoA/n, where n is the index of refraction of the sea water. Ao and A are the wavelengths as measured in the air and in the sea water respectively. 2t=(m+) (m = 0, 1, 2,...), A = Ao/n, where n is the index of refraction of the oil. Ag and A are the wavelengths as measured in the air and in the oil respectively. 2t=m (m = 0, 1, 2,...), A = Ao/n, where n is the index of refraction of the sea water. Ag and A are the wavelengths as measured in the air and in the water respectively. 2t m (m = 0, 1, 2,...), AA/n. where is the index of refraction of the oil. A and A are the wavelengths as measured in the air and in the oil respectively. 2t=(m+) (m = 0, 1, 2, ...), A = 0/n, where n is the index of refraction of the sea water. Ag and A are the wavelengths as measured in the air and in the sea water respectively. 2t=(m+) (m = 0, 1, 2,...), A = A/n, where n is the index of refraction of the oil. Ag and A are the wavelengths as measured in the air and in the oil respectively. Submit EXECUTE Previous Answers Correct The reflected light passes through the film twice, so the effective optical thickness is 2tn. Since the reflected ray from the first surface of the film gives an additional half wavelength, constructive interference is occurred for a thickness equal to (m+) A. Part C Find the wavelengths for which there is constructive interference as seen from above the oil film. Choose the wavelengths which are more comfortably in the visible spectrum. Enter your answers numerically in nanometers, separated by commas. View Available Hint(s) Aconst. 441,735 nm Submit Previous Answers Correct Solve the equation from part B. A = 2tn/(m +0.5). Only two wavelengths are in visible spectrum: for m = 1 and m = 2. Part D What color is the light? Select all that apply. View Available Hint(s) Violet Blue Green Yellow Orange Red Submit Previous Answers Correct The wavelength of 441 nm is corresponds to the violet and the wavelength of 735 nm is corresponds to the red. Part E Find the visible wavelength for which there is destructive interference as seen from above the film. Express your answer in nanometers. View Available Hint(s) Adistr.= Submit ? nm Part F What color is the light? Check all that apply. View Available Hint(s) Violet Blue Green Yellow Orange Red Submit EVALUATE