A 5-cm-high object is placed in front of a concave mirror with a radius of curvature of 20 cm. Answer the following question (show your work in details)
1) Determine the image height if the object distance is 20 cm .
2) Determine the image height if the object distance is 40 cm
3) Mention the characteristics of the image formed in both cases, in part (1) and part (2).

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.

b. a lightning bug, plug of grass, and a worm

its a circle not a square that's simple silly.

explanation: