Question

What is the speed of light in (a) crown glass n= 1.52, (b) Lucite n = 1.51, and (c) ethyl alcohol n = 1.36?

Answer 1

Answer:

$(a)\\1.97\times 10^8 m/s\\(b)\\1.99\times 10^8 m/s \\(c)\\2.21 \times 10^8 m/s$

Explanation:

According to the definition of refractive index, the refractive index of the material is defined as the ratio of speed of light in vacuum to the speed of light in medium.

(a) refractive index, n = 1.52

$n=\frac {c}{v}\\\\1.52 = \frac{3\times 10^8}{v}\\\\v = 1.97\times 10^8 m/s$

(b) refractive index, n = 1.51

$n=\frac {c}{v}\\\\1.51 = \frac{3\times 10^8}{v}\\\\v = 1.99\times 10^8 m/s$

(c) refractive index, n = 1.36

$n=\frac {c}{v}\\\\1.36 = \frac{3\times 10^8}{v}\\\\v = 2.21\times 10^8 m/s$