What fraction of light is reflected from the air water interface?

AI Thread Summary
The discussion centers on calculating the fraction of light reflected at the air-water interface using the reflection coefficient formula R = ((n2 - n1) / (n1 + n2))^2, with n1 = 1 and n2 = 1.33. Initial calculations suggest that approximately 25% of light is reflected, but some participants argue that the correct reflection coefficient is closer to 2%, based on their calculations. Discrepancies arise from miscalculations, particularly in the denominator, leading to confusion about the correct values. Ultimately, the consensus is that about 2% of light is reflected, while 98% is transmitted. Accurate interpretation of the reflection coefficient is crucial for understanding light intensity reflections from bodies of water.
stunner5000pt
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What fraction of light is reflected from the air water interface? i.e. How intense is your reflection from a lake?

since the reflection coefficient is R = (\frac{n_{2} - n_{1}}{n_{1} + n_{2}})^2

n1 = 1 and n2 = 1.33 so R = 0.248. I am not sure how to interprete this?

25% of the light reflects?? is that the appropriate answer?
 
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stunner5000pt said:
What fraction of light is reflected from the air water interface? i.e. How intense is your reflection from a lake?

since the reflection coefficient is R = (\frac{n_{2} - n_{1}}{n_{1} + n_{2}})^2

n1 = 1 and n2 = 1.33 so R = 0.248. I am not sure how to interprete this?

25% of the light reflects?? is that the appropriate answer?

Yes. 25% is reflected. 75% is transmitted (refracted).

EDIT: Check your calculation. I get R=0.02, So 2% is reflected.
 
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learningphysics said:
Yes. 25% is reflected. 75% is transmitted (refracted).
so th fraction would be 1/4 right? Thanks for the help!
 
stunner5000pt said:
so th fraction would be 1/4 right? Thanks for the help!

I get R=0.02
 
As did I. R = .02
 
i think you are forgetting to square it it's (0.33/1.33)^2 = 0.062
 
Nope.

(\frac{1.33-1}{1 + 1.33}) = .1416...

.1416309^2 = .020059...

I don't see the problem.

EDIT: You divided by the wrong number...it's 2.33 not 1.33
 
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