A beam of light passes from air to ethanol, with index of refraction of 1.36. If the angle of incidence (1) is 30.0 degrees, then calculate he angle of refraction, after light passes through ethanol and enters into air.
I got 30.0 because wouldn't the light beam upon re-entering air be parallel to the original?
yes.
To calculate the angle of refraction, you can use Snell's Law, which relates the angles of incidence and refraction to the indices of refraction of the two media.
Snell's Law states:
n1 * sin(θ1) = n2 * sin(θ2)
where:
n1 = index of refraction of the first medium (air in this case)
n2 = index of refraction of the second medium (ethanol in this case)
θ1 = angle of incidence
θ2 = angle of refraction
Given that the angle of incidence (θ1) is 30.0 degrees and the index of refraction of ethanol (n2) is 1.36, we can substitute these values into Snell's Law:
1 * sin(30.0 degrees) = 1.36 * sin(θ2)
To find the angle of refraction (θ2), we can rearrange the equation as follows:
sin(θ2) = (sin(30.0 degrees)) / 1.36
Taking the inverse sine of both sides gives:
θ2 = arcsin((sin(30.0 degrees)) / 1.36)
Evaluating this expression gives:
θ2 ≈ 21.4 degrees
So, the angle of refraction when the light passes from ethanol back into air is approximately 21.4 degrees. This means the light ray will not be parallel to the original direction.