A ray of light λ = 589nm is incident from water to air, at an angle (relative to the normal) of 20.8o. What is the angle of refraction? (NOTE: You are missing some information; you will need to look it up.

Enter your answer in degrees.

Question

A ray of light λ = 589nm is incident from water to air, at an angle (relative to the normal) of 20.8o. What is the angle of refraction? (NOTE: You are missing some information; you will need to look it up.

Enter your answer in degrees.

anonymous · Answer

index of refraction for any medium=speed of light in one medium/medium of light in the second medium
when light travels from air to water,the index of refraction is 1.5.From this,you can find the velocity of light in water.
In your question,light is travelling from water to air,so either u take water as the first medium and air as the second or the index of refraction for light travelling from water to air will be reverse of that when it travels from air to water,i.e. 1/(1.5)
and as I said in previous question,then u can find the angle of refraction.