The Magic coin trick.
Refraction of light.
Why does light bend when it travels from one medium to another?
Click to see an animation
What if the ray of light travels perpendicular to the surface of the water, as shown on the right, which way will it bend?
Solution
How to predict which way the ray will bend.
Draw a line perpendicular to the surface where both mediums meet. This is called the normal.
A ray travelling from a medium with a relatively high refractive index to one with a relatively low refractive index will bend away from the normal.
A ray travelling from a medium with a relatively low refractive index to one with a relatively high refractive index will bend towards the normal
The image on the right shows a beam of light, as waves, passing from air into water.
What can you say about the speed, frequency and the wavelength of light as it passes from air into water?
Is the light bending towards or away from the normal as it passes from air into water?
