What is refractive index?Please explain very nicely

Question

surry99 · Answer

Do you know what the term refractions means?

ookawaiioo · Answer

It related to speed of light......

surry99 · Answer

not quite....google it it relates to waves in general...

anonymous · Answer

I thought that was Lenz's Law?

anonymous · Answer

If you are in introductory physics, then the following will help u understand

When light goes from air to glass it is found to bend, change directions.. we call this as refraction of light. 
The reason light bends is cause the speed of light changes. Its found that light slows down by a factor of 1.5. (its speed becomes 1.5 times less) when it goes from air to glass.. this factor is called the refractive index.
So its basically how much SLOWER light is in any given medium compared to air

thus speed of light in glass = C/1.5 = 2 X 10^8

Refractive index of water is 1.33 can u tell me what is the speed of light in water?!

P.S. Does refractive index have any units?!

anonymous · Answer

Thanks Mashy