UNIT C: LIGHT AND OPTICS

STUDY NOTESMr.Ilko

CONCAVE VS CONVEX LENSES/MIRRORS Concave lens – a sunken in piece of glass that causes

light to spread out when light passes through it

Convex Lens – a bulged piece of glass that causes light to bend to a focal point when passed through it

Concave mirror – a sunken in piece of glass that bounces light into a focal point

Convex mirror – a bulged out piece of glass that bounces light away from its original path

Focal point only happen on concave mirrors and convex lenses in reality, the other two have imaginary focal points

PROPERTIES OF LIGHT ACRONYMN --- SERB

S – Straight – light travels in straight lines

E – Energy – Light is a form of energy R – Reflected – light can be reflected B – Bent – Light can be bent

LIGHT AND OBJECTS Luminous – light (how bright it is)

Transparent – Almost all of the light is able to get through

Translucent – Some light is able to get through and a small shadow is created

Opaque – no light is able to get through, and a shadow is cast

REFLECTION Regular Reflection – when the ray of

light hits off a smooth surface and bounces off at the same angle it came in atEx. Jacket reflectors

Diffuse Reflection – When light hits off a rough surface and is scattered on random directions and different anglesClothing around reflector tape

EYES Laser Eyes surgery – reshapes the

cornea of the eye

Compound eye – Usually on insects…eye is broken up into individual parts called ommatidium

Camera eye – Human eye that is round, has a cornea, retina and pupil

RODS AND CONES Rods – High sensitivity to light

Cones – Colour detectorsHumans see in RED, GREEN, BLUE ---

NOTHING ELSE!!!!!

In TV’s we see a colour like yellow by red and green rods being close together

WAVES Amplitude – The height of the Crest from

the resting point

Wavelength – distance from the beginning of a wave to the end

Frequency – How often a wave length occurs in a given time frame

BIOLUMINESCENCE The ability for animals to produce their

own lightUsually happens due to a chemical reaction

or bacteria

DIFFERENT TYPES OF LIGHT BULBS Fluorescent – Uses electricity passing

through a gas in order to spark and create light

Incandescent – Uses a heated up metal coil in order to produce light

Phosphorescent – Uses UV light on a phosphor coating to produce light

ELECTROMAGNETIC SPECTRUM 7 Ranges

Radio Waves Microwaves Infrared wavesVisible Spectrum -- ROYGBIVUltra-violet wavesX-RaysGamma Rays

PARTS OF THE EYE TO KNOW Iris Pupil Retina Lens Cornea