Answer:
157077501.7 m/s
Explanation:
Refractive index of water = n₂ = 1.33
θ₁ = 14.5°
θ₂ = 21.8°
According to Snell's law
[tex]\frac{sin\theta_1}{sin\theta_2}=\frac{n_2}{n_1}\\\Rightarrow n_1\times sin\theta_1=n_2\times sin\theta_2\\\Rightarrow n_1\times sin14.5=1.33\times sin 21.8\\\Rightarrow n_1=\frac{1.33\times sin 21.8}{sin14.5}=1.972[/tex]
Refractive index of plastic is 1.973
[tex]n=\frac{c}{v}\\\Rightarrow v=\frac{c}{n}\\\Rightarrow v=\frac{3\times 10^8}{1.973}=157077501.7\ m/s[/tex]
∴ Speed of light in the plastic cube is 157077501.7 m/s
