A thin biconvex lens, made of glass having n=1.54, has its radii of curvature R1 = 40.2 cm and R2 = 49.6 cm. (a) Calculate its focal length. This lens focuses the image of a lighted object placed 64.0 cm in front of it so that a sharp/clear image is obtained on a screen. Now a second lens is placed 35.0 cm behind the first one. To get the new image in focus the screen must be moved to be 10.1 cm behind the second lens. (b) Find the focal length of the second lens. 1

A thin biconvex lens, made of glass having n=1.54, has its radii of curvature R1 = 40.2 cm and R2 = 49.6 cm. (a) Calculate its focal length. This lens focuses the image of a lighted object placed 64.0 cm in front of it so that a sharp/clear image is obtained on a screen. Now a second lens is placed 35.0 cm behind the first one. To get the new image in focus the screen must be moved to be 10.1 cm behind the second lens. (b) Find the focal length of the second lens. 1