A fish in water (refractive index n ) looks at a bird vertically above in the air. If y is the height of the bird and x is the depth of the fish from the surface, then the distance of the bird as estimated by the fish is

Step-by-step solution

The fish is at a depth x below the water surface. The bird is at a height y above the water surface. When an observer in a medium of refractive index n₁ looks at an object in a medium of refractive index n₂ , the apparent depth or height is given by the formula d_ apparent = d_ actual n_ observer n_ object . Here, the fish is the observer in water (refractive index n ) and the bird is the object in air (refractive index 1 ). The actual distance of the bird from the surface is y . The apparent distance of the bird a