Hi. I have some homework questions here that I need a little help on. I know the fomulae to use just do not know how to apply it properly. Any help will be appreciated. In a Newton's Ring experiment, a planoconvex glass (n=1.54) lens having a diameter 14.3 cm is placed on a flat plate. When 585 nm light is incident normally, 8 bright rings are observed with the last one right on the edge of the lens, at r. 1. What is the thickness of the lens? 2. What is the radius of curvature of the convex surface of the lens? 3. What is the focal length of the lens?