Question

What is the index of refraction of a medium in which light travels at 1.89x10^8m/s

Answer 1

n=index of refraction

c=speed of light in a vacuum $(3\times10^8\frac{m}{s})$

v=speed of light in the other medium$(\frac{m}{s})$

$n=\frac{c}{v}$

$n=\frac{3\times10^8\frac{m}{s}}{1.89\times 10^8\frac{m}{s}}$

$n=1.59$