Light and refraction in water

In summary, two problems were discussed in this conversation. The first problem involved a narrow beam of sodium yellow light with a wavelength of 589 nm in vacuum being incident onto a smooth water surface at an angle of incidence of 35.0 degrees. The angle of refraction was determined to be 25.486 degrees and the wavelength of the light in water was found to be 441.86 nm. The second problem involved unpolarized light in vacuum being incident onto a sheet of glass with an index of refraction n. The reflected and refracted rays were found to be perpendicular to each other, and the angle of incidence was determined to be tan^-1(n).
  • #1
Bri
20
0
Could someone tell me if I did this right?
A narrow beam of sodium yellow light, with wavelength 589 nm in vacuum, is incident from air onto a smooth water surface at an angle of incidence of 35.0 degrees. Determine the angle of refraction and the wavelength of the light in water.
I did...
sin(35 degrees)=1.333*sin(theta)
theta = 25.486 degrees

589 nm = 1.333*lambda
lambda = 441.86

I'm just not sure I used the right equation/setup.

And I can't figure out this problem...
Unpolarized light in vacuum is incident onto a sheet of glass with index of refraction n. The reflected and refracted rays are perpendicular to each other. Find the angle of incidence.
I figured Theta1 + Theta2 = 90 degrees
and I tried to find a way to solve it using sin(Theta1) = n*sin(Theta2) but it's not working out.

Thanks.
 
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  • #2
The first part looks right to me I guess. Think about [tex]\Theta_2 = 90 - \Theta_1[/tex] and plug it into your formula. Remember that sin(90-x) = cos(x)
 
  • #3
vsage said:
The first part looks right to me I guess. Think about [tex]\Theta_2 = 90 - \Theta_1[/tex] and plug it into your formula. Remember that sin(90-x) = cos(x)

I've tried it that way, I wasn't able to get anywhere with it.
 
  • #4
I don't really see a definitive answer for part 2, but since [tex]sin(\theta_1) = n\times cos(\theta_1)[/tex], [tex]\theta_1 = tan^{-1}(n)[/tex]
 
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1. What causes light to bend when it enters water?

Light bends when it enters water due to the change in the speed of light as it passes from air to water. This change in speed is caused by the difference in the density of air and water, which leads to a change in the direction of the light ray.

2. How does the angle of refraction change as the angle of incidence increases?

The angle of refraction also increases as the angle of incidence increases. This is due to the relationship between the speed of light and the angle of refraction, known as Snell's Law. As the angle of incidence increases, the light ray is bent more as it enters the water, resulting in a larger angle of refraction.

3. What is the critical angle of refraction?

The critical angle of refraction is the angle at which the light ray is no longer refracted, but instead is reflected back into the original medium. This occurs when the angle of incidence is greater than the critical angle, and is dependent on the indices of refraction of the two mediums.

4. How does the refraction of light in water affect the appearance of objects underwater?

The refraction of light in water can make objects appear closer, larger, and distorted when viewed from above the water's surface. This is due to the change in the direction of light rays as they pass from water to air, resulting in a different angle of incidence for each point on the object.

5. How does the depth of water affect the refraction of light?

The depth of water can affect the refraction of light in several ways. The deeper the water, the greater the change in the speed of light, resulting in a greater angle of refraction. Additionally, objects at the bottom of deep water may appear to be shifted or distorted due to the refraction of light passing through multiple layers of water before reaching the viewer's eye.

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