An object is placed as shown in front of a concave mirror. the image of the object will be inverted (upside down) upright diminished in size enlarged real virtual

Explanation :

The spherical mirrors are of two types i.e. concave mirror and the convex mirror.

The mirror whose reflecting surface bulges inwards are called concave mirrors. It is also known as converging mirror. Th attached figure shows a concave mirror.

The image formed by concave mirror is real inverted. There is only one case when the formed image is virtual and erect when the object is placed in between the pole and the focus.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.