Consider a lens having index of refraction n₂ and surfaces with radii R₁ and R₂. The lens is immersed in a fluid that has index of refraction n₁.
a. Derive a generalized lens maker’s equation to replace Equation 34.26 when the lens is surrounded by a medium other than air. That is, when n₁ ≠ 1.
b. A symmetric converging glass lens (i.e., two equally curved surfaces) has two surfaces with radii of 40 cm. Find the focal length of this lens in air and the focal length of this lens in water.