When I was little, my mom was making tea for me, she used a transparent cup, poured water in it and put in the tea spoon 🥄 then she stood to open the powdered milk 🥛can. I looked down at the cup🥃 and told my mom something “Mom, the spoon’s broken”. My mom looked down in surprise and noticed what I noticed then she smiled.
When the spoon 🥄was inside the water from air, it is refracted from a less dense medium to a denser medium.
Refraction occurs in glass to air, air to glass, water to air, air to water, water to glass, glass to water.etc.
Refraction from air to water.
Refractive Index is used to express the nature of medium through which light ray is propagated. It is denoted by the symbol μ
The refractive index from air to water is
aμg = real depth ÷ apparent depth.
aμg = 4/3
A coin is placed at the bottom of of a pond,3m deep. Calculate the apparent depth of the coin when it is viewed directly from the top. Taking aμg = 4/3.
Solñ
μ = real depth ÷ apparent depth.
4/3 = 3 ÷ apparent depth
Making apparent depth the subject of formula,
Apparent depth = 3 ÷ 4/3 = 3/1 ÷ 3/4 = 2.25.
Refraction from air to glass
Source
aμg = 1.5
When light is passed from air to glass,it bends away from the source. Except if it is a triangular prism.
aμg = sin i ÷ sin r
A ray of light is incidented at an angle of 60° in air on a glass surface. Find the angle of refraction of the glass.
Solñ
aμg = 1.5
aμg = sin i ÷ sin r
1.5 = sin 60 ÷ sin r
Sin r = 0.8660 ÷ 1.5
Sin r = 0.5773
r = sin-¹0.5773
r = 35.2.
Another formula we need in this topic is
D = t (1-1/μ)
Where D is displacement, μ is the refractive index, t is the thickness of the medium
A microscope is focused on a table when a mark is covered by a plate of glass, 3cm thick. The microscope has to be placed 1.18cm for the mark to be on a small focus. Calculate the refractive index of the medium.
Solñ
D = 1.18
t = 3
μ = ?
D = t-t/μ
Making μ the subject of formula
μ = D–t/-t
μ = -3/1.18-3
μ = 1.648 ≈ 1.65.
This is where I'm stopping so far.
Thanks for stopping by.
It's great to see some scientific and intelligent explanations for these life occurrences!!
Am so glad you got to understand them.