Physics - 14 Light - 14.1 Reflection of Light & 14.2 Refraction of Light & 14.3 Light and Colour

Incident wave

wave that strikes the boundary

Reflected wave

wave that bounces back from a barrier

Normal

line perpendicular to a surface

Angle of incidence

angle between the incident ray and the normal

Angle of reflection

angle between the reflected ray and the normal

Virtual image

image that forms at a location from which light rays appear to come but do not actually come

Plane mirror

mirror with a flat surface

Specular reflection

reflection of light off a smooth surface

Diffuse reflection

reflection of light from a rough surface

Refraction

bending of a wave as it passes at an angle from one medium to another

When light enters a less dense medium, it bends (towards/away from) the normal

away from

When light enters a denser medium, it bends (towards/away from) the normal

towards

Why do refracted waves have a smaller amplitude?

reflection at the boundary

When light enters a denser medium, the wavelength (increases/decreases/stays the same)

decreases

When light enters a denser medium, the wave speed(increases/decreases/stays the same)

decreases

When light enters a denser medium, the frequency (increases/decreases/stays the same)

stays the same

White light

light containing all the colours of the visible light spectrum

The colour of light is dependent on its...

wavelength and frequency

Dispersion

separation of frequencies by refraction

Red has the (longest/shortest) wavelength

longest

Purple has the (longest/shortest) wavelength

shortest

Colour mnemonic

Richard 'Opes Your Grey Cat Bites People

Light filter

transparent device that allows only certain wavelengths of light to be transmitted

Primary colours of light [3]

- red

- blue

- green

Red + blue

magenta

Blue + green

cyan

Green + red

yellow

Red + blue + green

white

Pigment

element, compound or molecule that absorbs and reflects specific colours

Translucent

allowing light to pass through diffusely

Opaque

not allowing light to pass through - absorbing or reflecting it instead