9. A tank holds a layer of oil, 1.43 m thick, that floats on a layer of syrup that is 0.64 m thick. Both liquids are clear and do not intermix. A ray originates at the bottom of the tank at the
intersection with a vertical axis. It crosses the oil-syrup interface at a point 0.90 m from the
axis, then continues through the oil. It arrives at the oil-air interface at a distance 2.00 m from
the axis and at the critical angle. What is the index of refraction of the oil?
air
2.00 m