What is refraction of light?
Refraction of light refers to the change of direction when light travels from one substance to a different substance.
How will the light change its direction?
If a light travels from a less dense substance to a denser substance, such as from air to water, the light will slow down. As the light slows down, it will travel towards the normal line.
In a less dense substance (faster), the light travels away from the normal line. In a denser substance (slower), the light changes direction towards the normal line.
There is an equation that summarizes this relationship!
When light travels from air to another substance, use this equation:
n=sin(i)/sin(r)
n = refractive index of the substance
i = angle of incidence
r = angle of refraction
TIPS:
I. Refractive index is a measure of how fast light travels through the material.
II. Angle of incidence and angle of refraction is always the angle made by the light ray and the normal line!
Let's look at an example!!
Calculate the angle of refraction when the angle of incident is 60° and the refractive index of water is 1.33.
Step 1. Substitute all the known variables into the equation.
1.33=sin(60°)/sin(r)
Step 2. Rearrange the equation to solve for r.
sin(r)=sin(60°)/1.33=0.65
Step 3. Solve for r.
r=41°