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
When light waves travel from a fast to a slow medium, as whoen on the right, their direction chagnes.
What happens to the speed of the waves, shown on the right, as they pass from one medium into another?
What happens to the wavelength (distance between each wave)?
