During the study of the light and geometric optics unit, chapter 12.4, we learned the Index of Refraction.
Definitions:
Index of Refraction:
The ratio of the speed of light in a vacuum compared to the speed of light in a medium
Refracted Ray:
A ray that has entered a medium and has bent either away or towards the normal depending of the density of the object.
Mathematically the ratio of the index of refraction is written as;
'N' is the index of refraction whereas 'C' is the speed of light in a vacuum and 'V' is the speed of light in a given medium.
The index of refraction can also be calculated by the using the sines of the angles.
N = sin i
sin r
Calculating the Index of refraction:
You are given;
The speed of light in a vacuum is
C=3.00 x 10 to the power of 8 meters a second.
You are also given the speed of light in the given substance for example sodium chloride.
V (sodium chloride) =1.96 x 10 to the power of 8 meters a second.
Solution:
N = C
V
= 10 to the power of 8 m/s
1.96 x 10 to the power of 8 m/s
= 1.53
Therefore the index of refraction for sodium chloride is 1.53.
Calculating the speed of light.
You are given;
The speed of light in a vacuum is C=3.00 x 10 to the power of 8 meters a second.
and the index of refraction in a given substance for example olive oil
where N(olive oil) =1.48
you must then find V or the speed of light in the given medium (Olive oil).
Solution:
N = C
N
V x N = C
V = C
V
= 3.00 x 10 to the power of 8 m/s
1.48
= 2.03 x 10 to the power of 8 m/s
therefore the speed of light in olive oil is = 2.03 x 10 to the power of 8 m/s
Snell's Law:
Snell's law is a formula to describe the relationship between the angle of incidences and the angle of refraction.
Here's a link for a quick lesson on the index of refraction
http://www.youtube.com/watch?v=iuBiZjSHnwI
Here's one for the calculations on the index of refraction.
http://www.youtube.com/watch?v=wuD2pwqyT3Q
Here's one for Snell's Law.
http://www.youtube.com/watch?v=y55tzg_jW9I
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