angle of refraction at the surface of water?

I have done saveral questions on refrective indexes and used the equation

N = sin i/ sin r

but i coudnt associate the below question with the formula as its asking me at the surface.. (Im not sure whether the above formula would be correct for this situation?)

A light ray in water is directed at the water surface at an angle of incidence of 40 degrees.

Calculate the angle of refraction of the light at this surface?

You know i.
You know N.
So rearrange to find r.

I'm not sure what the problem is here. You say you have done several questions already. This is about the simplest I can think of - what were they?

I have done saveral questions on refrective indexes and used the equation

N = sin i/ sin r

but i coudnt associate the below question with the formula as its asking me at the surface.. (Im not sure whether the above formula would be correct for this situation?)

A light ray in water is directed at the water surface at an angle of incidence of 40 degrees.

Calculate the angle of refraction of the light at this surface?

The answer that you get is you do that is 28.9 degrees. The textbook answers say the answer should be 58.7 degrees...

So clearly your method isn't enough...?

A light ray in water is directed at the water surface at an angle of incidence of 40 degrees.

i) Calculate the angle of refraction of the light ray at this surface.

ii) Sketch the path of the light ray showing the normal and the angles if incidence and refraction.

The answer that you get is you do that is 28.9 degrees. The textbook answers say the answer should be 58.7 degrees...

So clearly your method isn't enough...?

Snells' law says

sin(i)/sin(r) = n_r/n_i

if the ray starts in air and is incident on a boundary with water
n_r/n_i
evaluates to n_r/1.0 = n_r
because the refractive index of air is 1.0

if the ray starts in water and is incident on a boundary with air you need to work out the fraction.

PS this thread is 9 years old - it's better to start a new thread when you have a problem

PS this thread is 9 years old - it's better to start a new thread when you have a problem

the correct way to answer this question is by multiplying the refractive index by the angle of refraction so, 1.33 * sin(40) = Sin-1(Ans). [This is in a calculator by the way]= 58.7I know the question asks calculate the angle of refraction but it can only be done by actually calculating the angle of incidence so your welcome guys