The class is about heat, waves, and light. The website wants exactly the perfect answer and in the same metric system units that are stated on the calculators that are on the picture for the question, if not, it'll mark it wrong.

A planoconvex lucite lens of diameter d is placed on a at piece of glass. When light of wavelength 1 is incident normally, 48 bright rings are observed, the last one right at the edge. a. What is the radius of curvature R of the lens surface? Express your answer in terms of the quantities d and l. Find the thickness t of the air gap at the edge of the lens rst. Write down the condition for constructive interference. Be careful to note the phase shifts when light in glass reects off air. and when light in air reects off glass. Is the center point bright or dark? What is the path difference, in numbers of wavelengths, for the rst bright circle? For the 48th? To nd the radius of curvature, draw a diagram of the lens, showing the thickness t of the air gap at the edge of the lens, the radius of curvature R, and the radius r of the lens. Knowing] and r, you can nd R using geometry. b. Evaluate the radius of curvature numerically if d = 3.3 cm and it = 5% nm. Take care to check the units. c. Using the numerical values given in part b. what is the focal length of the lens