Now a new technique can. So according to the n s i n A D 2 s i n A 2. Light travels at approximately 300000 kilometers per second in a vacuum which has a refractive index of 10 but it slows down to 225000 kilometers per second in water refractive index 13.
Light travels at approximately 300000 kilometers per second in a vacuum which has a refractive index of 10 but it slows down to 225000 kilometers per second in water refractive index 13.
Sometimes c is used for the speed of waves in any material medium and c 0 for the speed of light in vacuum. Using the definition of n we can find the speed of light through lead. Different media reduce that speed by different amounts depending on their optical density. This video shows how to calculate the speed that light will travel at in a material with a known value of refractive index.