Question

Consider an underwater spherical air bubble (you can assume the index of refraction of air is 1 and water is 1.33) with radius R. This bubble can act as a lens. What is its focal length?

Answer 1

Answer:

-2R

Explanation:

The focal length can be calculated using this formula

1/f = (n1/n2-1)(1/r1-1/r2)

1/f = (1/1.33-1)(1/r + 1/r)

= -0.133/1.33(2/R)

F = -2R

The focal length is this