a small lightbulb suspended at distance 250 cm above the surface of the water in a swimming pool where the water depth is 200 cm. The bottom of the pool is a large mirror. How far below the mirror surface is the image of the bulb?
Dear Student,
See the diagram.
The apparent shift of the mirror within the water is, h = 200 (1 – 1/μ)
μ = 1.33 is the refractive index of water.
So, the apparent distance between the mirror and the bulb is = 450 – [200 (1 – 1/μ)] = 400.38 cm
The image is also formed at a distance 400.38 cm below this apparent position of the mirror.
Therefore, the actual distance between the mirror and the image is
= (400.38 - h) = 400.38 - [200 (1 – 1/μ)] = 350.76 cm