1)A beam of light passes from air to ethanol, with index of refracton of 1.36. If the angle of incidence ( 1)is 30.0 d/C, then calculate the angle of refraction, after light passes through ethanol and enters into air.
sin-1((1.0003/1.36)sin30.0
21.6 d/C
2)An ____ lens is used to produce a real image.
convex
wouldn't the light beam upon re-entering air be parallel to the original beam in the air?
concave lenses form virtual images. They are often called diverging lenses, because they spread light apart.
http://en.wikipedia.org/wiki/Virtual_image
To calculate the angle of refraction, we can use Snell's Law, which states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the indices of refraction of the two media.
In this case, the angle of incidence is given as 30.0° and the index of refraction of ethanol is 1.36.
Using Snell's Law: sin(θ1)/sin(θ2) = n2/n1
We can rearrange the equation to solve for the angle of refraction (θ2):
sin(θ2) = (n1/n2) * sin(θ1)
Where:
n1 = index of refraction of air = 1.0003
n2 = index of refraction of ethanol = 1.36
θ1 = angle of incidence = 30.0°
Plugging in the values, we have:
sin(θ2) = (1.0003/1.36) * sin(30.0°)
Using a scientific calculator, we can evaluate the expression:
sin(θ2) ≈ 0.444266
To find the angle of refraction (θ2), we use the inverse sine function (also known as arcsine or sin^-1):
θ2 ≈ sin^-1(0.444266)
Using a scientific calculator:
θ2 ≈ 21.6°
Therefore, the angle of refraction, after light passes through ethanol and enters into air, is approximately 21.6°.
Note: The final answer is rounded to one decimal place.