How is an image formed by a plane mirror?

light bounces off of the mirror and then appears to come from in front of the mirror.
light passes through the mirror and then appears to come from behind the mirror.
light passes through the mirror and then appears to come from in front of the mirror.
light bounces off of the mirror and then appears to come from behind the mirror.

Light bounces off of the mirror and then appears to come from behind the mirror.

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.