1. Determine the refractive index of a medium if the speed slows to 1.2 x 108 m/s
+37097 Straight from Wikipedia:
In optics, the refractive index or index of refraction n of a material is a dimensionless number that describes how light propagates through that medium. It is defined as
n = c/ v ,
where c is the speed of light in vacuum and v is the phase velocity of light in the medium. For example, the refractive index of water is 1.333, meaning that light travels 1.333 times faster in a vacuum than it does in water.
For this problem: n= (3x10^8) / (1.2 x 10^8) = 2.5
