SNC2D6 - Physics Unit

Location of images in plane mirrors

The point where the extensions of reflected rays meet behind the mirror.

Law of Reflection

The angle of incidence will be equal to the angel of reflection (measured at the normal).

Ray through focal point

Will bounce back parallel

Ray parallel to axis

Will bounce back through focal point

Ray through centre of curvature

Will bounce back through itself

SALT

Size, Attitude, Location, Type

Index of refraction

The density of a medium

Location of focal point

Halfway between mirror and centre of curvature

Incident ray

Light rays going towards the mirror

Reflected ray

Light rays that bounce off the mirror

Refracted ray

Direction of light when travelling from a less/more optically dense medium to a more/less optically dense medium

Principle of reversibility

Light will follow the exact same path if its direction of travel is reversed

Light travels from a slow (more ODM) medium to a fast (less ODM) medium

Angle of refraction is always bigger than the angle of incidence

Critical angle

An angle of incidence that provides an angle of refraction of 90 degrees

Cause of total internal reflection

Any angle of incidence greater than the critical angle

Total internal reflection

Reflection of all incident rays off the boundary

More ODM to less ODM

Bends away from normal

Less ODM to more ODM

Bends towards normal