4. The observer counts the width of 10 Newton's rings from their center. It is equal to 0.7 mm. The width of these rings 10 is equal to 0.4 mm in the light of the observation made at full length of λ = 589 nm, determine the radius of curvature of the lens surface.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)