1. The problem statement, all variables and given/known data A plane convex lens is made of glass (index 1.42) with one flat surface and the other having a radius of 24 cm. What is the focal length of the lens? Anwer in united of cm. 2. Relevant equations Lensmaker Equation 1/f=(n-1)*((1/r1)-(1/r2)) 3. The attempt at a solution f=1/[(n-1)*(1/r1)-(1/r2))] f=1/[(1.42-1)*((1/-24cm)-(1/0))] f=-57.142857 Is this right?? If the surface is flat on the lens, radius is given as 0 then correct? please check my work.