n:  Refractive index

v:  Speed of light (m/s)

c:  Speed of light in vacuum (m/s) = 3x108 m/s

 

n =

 

Light travels faster in air than in water, so refractive index more for water than that for air.

 

Snellís Law:

 

n1.sin θ1 = n2.sin θ2