we know that the speed of light in a vacuum is 3.0 x 10^8 m/s (18,000 mi/sec). If light travels through thick plastic with a speed of 1.75 x 10^8 m/s, what is the index of refraction through plastic?
1 answer
index of refraction= speed of light in space/speed of light in material=3.0/1.75=