Author Question: For a converging lens with two convex surfaces, the radius of curvature for both surfaces is 20 cm. ... (Read 139 times)

michelleunicorn · **on:** Jul 28, 2018

For a converging lens with two convex surfaces, the radius of curvature for both surfaces is 20 cm. If the focal length is 10 cm, what must the index of refraction be?
a. 1.5
c. 2.0
b. 2.5
d. 3.0

Question 2

How many atoms are present in a sample of pure iron with a mass of 210 g? (The atomic mass of iron = 56 u and NA = 6.02 1023.)
a. 1.8 1019
c. 2.3 1024
b. 2.3 1028
d. 3.2 1028