Given,
Light passes from material A, which has an index of refraction of 4/3 into material B, which has an index of refraction of 5/4.
To find: Find the ratio of the speed of light in material B to the speed of light in material A.
Solution:
The refractive index is inversely proportional to the speed of the light in the material.
[tex]\begin{gathered} \frac{n_A}{n_B}=\frac{v_B}{v_A} \\ \frac{\frac{4}{3}}{\frac{5}{4}}=\frac{v_B}{v_A} \\ \frac{v_{B}}{v_{A}}=\frac{16}{15} \end{gathered}[/tex]Thus, the ratio of the speed of light in the material B to the speed of light in material A is
[tex]\frac{v_B}{v_A}=\frac{16}{15}[/tex]
