Refraction and Reflection

Refraction and Reflection
Specification points: Refraction
 * 71 - know and understand that at the interface between medium 1 and medium 2 n1sinΘ1 = n2sinΘ2, where refractive index is n=c/v
 * 72 - be able to calculate critical angle sin C = 1/n
 * 73 - be able to predict whether total internal reflection will occur at an interface
 * 74 - understand how to measure the refractive index of a solid material
 * Refraction - the change in the speed of a wave caused by it passing across an interface (boundary) between media with different optical densities
 * The optical density refers to the speed of light in a medium - the more optically dense a medium is, the slower waves travel
 * The speed decreases because the wavelength decreases (frequency is set at the source of the wave, and remains constant)
 * Refractive index - ratio of the speed of light in one medium to another 1n2= v1/v2
 * Absolute refractive index - the ratio of the speed of light in a vacuum to the speed of light in a medium n = c/v
 * Snell's Law - 2n1 = n1/n2 = sin(i)/sin(r) = λ2/λ1 = v2/v1
 * Critical angle - angle of incidence which produces an angle of refraction of 90°
 * A critical angle only exists when light is moving from a more dense medium to a less dense medium.
 * Partial reflection will always occur at any boundary
 * Angle of reflection is always equal to angle of incidenceUntitled.png