Answer:
[tex]v=2.58\times10^8m/s[/tex]
Explanation:
The index of refraction is equal to the speed of light c in vacuum divided by its speed v in a substance, or [tex]n=\frac{c}{v}[/tex]. For our case we want to use [tex]v=\frac{c}{n}[/tex], which for our values is equal to:
[tex]v=\frac{c}{n}=\frac{299792458m/s}{1.16}=258441774.138m/s[/tex]
Which we will express with 3 significant figures (since a product or quotient must contain the same number of significant figures as the measurement with the least number of significant figures):
[tex]v=2.58\times10^8m/s[/tex]
