Answer
1.58
Work Step by Step
Find the index of refraction using equation 23–4. The speed of light in the material is determined by the given information.
$$n=\frac{c}{v}=\frac{3.00\times10^8m/s}{(0.500m)/(2.63\times10^{-9}s)}=1.58$$
Identify the material using Table 23–1; It is light flint glass.