A symmetric, double-convex, thin lens made of glass with index of refraction 1.52 has a focal length in air of 40.0cm. The lens is sealed into an opening in the left-hand end of a tank filled with water. At the right-hand end of the tank, opposite the lens, is a plane mirror 90.0cm from the lens. The index of refraction of the water is t.
(a) Find the position of the image formed by the lens-water-mirror system of a small object outside the tank on the lens axis and 70.0 cm to the left of the lens.
(b) Is the image real or virtual?
(c) Is it erect or inverted?
(d) If the object has a height of 4.00 mm, what is the height of the image?